Johannes Skaar

Professor - Teoretisk fysikk

English version of this page

E-post johannes.skaar@fys.uio.no

Mobiltelefon 48497352

Rom Ø373

Brukernavn

Besøksadresse Sem Sælands vei 24 Fysikkbygningen 0371 OSLO

Postadresse Postboks 1048 Blindern 0316 OSLO

Pressebilde Last ned visittkort

100% stilling ved Fysisk institutt, UiO. Tidligere NTNU.

Forskning

Fysikk: kvanteoptikk, elektromagnetisme, metamaterialer, fotonikk, kvanteinformasjon.

Undervisning

Høsten 2020: FYS3110 Kvantemekanikk.
Våren 2021: FYS1001 Innføring i fysikk.

Kompendium (pdf): Johannes Skaar: Elektromagnetisme (2017).

Emneord: lys, kvanteoptikk, kvantekryptering, kvanteinformasjon, kvantefysikk, elektromagnetisme, elektromagnetiske bølger, metamaterialer, fotonikk, fysikk i dagliglivet, matematikk i musikk.

Gulla, Jan & Skaar, Johannes (2021). Approaching Single-Photon Pulses. Physical Review Letters. ISSN 0031-9007. 126(7), s 073601 . doi: 10.1103/PhysRevLett.126.073601 Vis sammendrag
Single-photon pulses cannot be generated on demand, due to incompatible requirements of positive frequencies and positive times. Resulting states therefore contain small probabilities for multiphotons. We derive upper and lower bounds for the maximum fidelity of realizable states that approximate single-photon pulses. The bounds have implications for ultrafast optics; the maximum fidelity is low for pulses with few cycles or close to the onset, but increases rapidly as the pulse envelope varies more slowly. We also demonstrate strictly localized states that are close to single photons.
Hågenvik, Hans Olaf & Skaar, Johannes (2019). Magnetic permeability in Fresnel’s equation. Journal of the Optical Society of America. B, Optical physics. ISSN 0740-3224. 36(5), s 1386- 1395 . doi: 10.1364/JOSAB.36.001386 Fulltekst i vitenarkiv.
Skaar, Johannes (2019). Fresnel's equations in statics and quasistatics. European Journal of Physics. ISSN 0143-0807. 40(4) . doi: 10.1088/1361-6404/ab166b Fulltekst i vitenarkiv.
Skaar, Johannes; Hågenvik, Hans Olaf & Dirdal, Christopher Andrew (2019). Four definitions of magnetic permeability for periodic metamaterials. Physical review B (PRB). ISSN 2469-9950. 99(6) . doi: 10.1103/PhysRevB.99.064407 Fulltekst i vitenarkiv. Vis sammendrag
We state and compare four different definitions of magnetic permeability for periodic, artificial media, or metamaterials. The connections among them, and properties in general, are discussed in detail, including causality, passivity, symmetry, asymptotic behavior, and origin dependence. The analysis is limited to metamaterials made from linear and nonmagnetic constituents
Dirdal, Christopher Andrew; Hågenvik, Hans Olaf; Haave, Haakon Aamodt & Skaar, Johannes (2018). Higher order multipoles in metamaterial homogenization. IEEE Transactions on Antennas and Propagation. ISSN 0018-926X. 66(11), s 6403- 6407 . doi: 10.1109/TAP.2018.2863742 Fulltekst i vitenarkiv. Vis sammendrag
The higher order multipoles above the electric quadrupole are commonly neglected in metamaterial homogenization. We show that they nevertheless can be significant when the second-order spatial dispersive effects, such as the magnetic response, are considered. In this respect, they can be equally important as the magnetization and quadrupole terms, and should not be automatically neglected.
Dirdal, Christopher Andrew & Skaar, Johannes (2018). Diamagnetism and the dispersion of the magnetic permeability. European Physical Journal B : Condensed Matter Physics. ISSN 1434-6028. 91(6) . doi: 10.1140/epjb/e2018-80515-1 Fulltekst i vitenarkiv.
Joshi, Siddarth Koduru; Pienaar, Jacques; Ralph, Timothy C.; Cacciapuoti, Luigi; McCutcheon, Will; Rarity, John; Giggenbach, Dirk; Lim, Jin Gyu; Makarov, Vadim; Fuentes, Ivette; Scheidl, Thomas; Beckert, Erik; Bourennane, Mohamed; Bruschi, David Edward; Cabello, Adán; Capmany, Jose; Carrasco-Casado, Alberto; Diamanti, Eleni; Dušek, Miloslav; Elser, Dominique; Gulinatti, Angelo; Hadfield, Robert H.; Jennewein, Thomas; Kaltenbaek, Rainer; Krainak, Michael A.; Lo, Hoi-Kwong; Marquardt, Christoph; Milburn, Gerard; Peev, Momtchil; Poppe, Andreas; Pruneri, Valerio; Renner, Renato; Salomon, Christophe; Skaar, Johannes; Solomos, Nikolaos; Stipčević, Mario; Torres, Juan P.; Toyoshima, Morio; Villoresi, Paolo; Walmsley, Ian; Weihs, Gregor; Weinfurter, Harald; Zeilinger, Anton; Żukowski, Marek & Ursin, Rupert (2018). Space QUEST mission proposal: experimentally testing decoherence due to gravity. New Journal of Physics. ISSN 1367-2630. 20:063016(6), s 1- 22 . doi: 10.1088/1367-2630/aac58b Fulltekst i vitenarkiv.
Hågenvik, Hans Olaf; Bløtekjær, Kjell & Skaar, Johannes (2017). Dielectric media considered as vacuum with sources. American Journal of Physics (AJP). ISSN 0002-9505. 85(11), s 830- 833 . doi: 10.1119/1.5003810 Fulltekst i vitenarkiv.
Marøy, Øystein; Makarov, Vadim & Skaar, Johannes (2017). Secure detection in quantum key distribution by real-time calibration of receiver. Quantum Science and Technology. ISSN 2058-9565. 2(4) . doi: 10.1088/2058-9565/aa83c9 Fulltekst i vitenarkiv.
Dirdal, Christopher Andrew; Bondevik, Tarjei & Skaar, Johannes (2015). Relaxed dispersion constraints and metamaterial effective parameters with physical meaning for all frequencies. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. 91(13) . doi: 10.1103/PhysRevB.91.134102
Dirdal, Christopher Andrew & Skaar, Johannes (2015). Superposing Lorentzian resonance functions towards engineering target responses, In Said Zouhdi; Nikolay Zheludev & Jing Hua Teng (ed.), Meta'14 Singapore Proceedings. META conference. ISBN 978-2-9545460-4-9. Artikkel. s 53 - 58
Hågenvik, Hans Olaf; Malema, Markus Edward & Skaar, Johannes (2015). Fourier theory of linear gain media. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 1050-2947. 91(4) . doi: 10.1103/PhysRevA.91.043826
Hågenvik, Hans Olaf & Skaar, Johannes (2015). Fourier-Laplace analysis and instabilities of a gainy slab. Journal of the Optical Society of America. B, Optical physics. ISSN 0740-3224. 32(9), s 1947- 1953 . doi: 10.1364/JOSAB.32.001947
Svendsen, Guro Kristin; Skaar, Johannes; Weman, Helge & Dupertuis, Marc-André (2015). Symmetries and optical transitions of hexagonal quantum dots in GaAs/AlGaAs nanowires. Physical Review B. Condensed Matter and Materials Physics. ISSN 1098-0121. 92(20) . doi: 10.1103/PhysRevB.92.205303
Bugge, Audun Nystad; Sauge, Sebastien; Ghazali, Aina Mardhiyah M.; Skaar, Johannes; Lydersen, Lars Vincent Van de Wiel & Makarov, Vadim (2014). Laser damage helps the eavesdropper in quantum cryptography. Physical Review Letters. ISSN 0031-9007. 112(7:070503) . doi: 10.1103/PhysRevLett.112.070503
Liu, Qin; Lamas-Linares, Antia; Kurtsiefer, Christian; Skaar, Johannes; Makarov, Vadim & Gerhardt, Ilja (2014). A universal setup for active control of a single-photon detector. Review of Scientific Instruments. ISSN 0034-6748. 85(1) . doi: 10.1063/1.4854615
Marøy, Øystein; Gudmundsen, Magne; Lydersen, Lars Vincent Van de Wiel & Skaar, Johannes (2014). Error estimation, error correction and verification in quantum key distribution. IET Information Security. ISSN 1751-8709. 8(5), s 277- 282 . doi: 10.1049/iet-ifs.2012.0333
Dirdal, Christopher Andrew & Skaar, Johannes (2013). Negative refraction in causal media by evaluating polar paths for rational functions. Journal of the Optical Society of America. B, Optical physics. ISSN 0740-3224. 30(2), s 370- 376 . doi: 10.1364/JOSAB.30.000370
Dirdal, Christopher Andrew & Skaar, Johannes (2013). Superpositions of Lorentzians as the class of causal functions. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 1050-2947. 88(3) . doi: 10.1103/PhysRevA.88.033834
Svendsen, Guro Kristin; Haakestad, Magnus Willum & Skaar, Johannes (2013). Reciprocity and the scattering matrix of waveguide modes. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 1050-2947. 87(1) . doi: 10.1103/PhysRevA.87.013838
Skaar, Johannes & Haakestad, Magnus Willum (2012). Inverse scattering of dispersive stratified structures. Journal of the Optical Society of America. B, Optical physics. ISSN 0740-3224. 29(9), s 2438- 2445 . doi: 10.1364/JOSAB.29.002438 Vis sammendrag
We consider the inverse-scattering problem of retrieving the structural parameters of a stratified medium consisting of dispersive materials, given knowledge of the complex reflection coefficient in a finite frequency range. It is shown that the inverse-scattering problem does not have a unique solution in general. When the dispersion is sufficiently small, such that the time-domain Fresnel reflections have durations less than the round-trip time in the layers, the solution is unique and can be found by layer peeling. Numerical examples with dispersive and lossy media are given, demonstrating the usefulness of the method for, e.g., terahertz technology.
Svendsen, Guro Kristin; Weman, Helge & Skaar, Johannes (2012). Investigations of Bragg reflectors in nanowire lasers. Journal of Applied Physics. ISSN 0021-8979. 111(12) . doi: 10.1063/1.4729529
Andresen, Marte Pernille Hatlo; Krogstad, Harald E & Skaar, Johannes (2011). Inverse scattering of two-dimensional photonic structures by layer stripping. Journal of the Optical Society of America. B, Optical physics. ISSN 0740-3224. 28(4), s 689- 696 . doi: 10.1364/josab.28.000689
Gerhardt, Ilja; Liu, Qin; Lamas-linares, Antia; Skaar, Johannes; Kurtsiefer, Christian & Makarov, Vadim (2011). Full-field implementation of a perfect eavesdropper on a quantum cryptography system. Nature Communications. ISSN 2041-1723. 2(349) . doi: 10.1038/ncomms1348 Fulltekst i vitenarkiv. Vis sammendrag
Quantum key distribution (QKD) allows two remote parties to grow a shared secret key. Its security is founded on the principles of quantum mechanics, but in reality it significantly relies on the physical implementation. Technological imperfections of QKD systems have been previously explored, but no attack on an established QKD connection has been realized so far. Here we show the first full-field implementation of a complete attack on a running QKD connection. An installed eavesdropper obtains the entire 'secret' key, while none of the parameters monitored by the legitimate parties indicate a security breach. This confirms that non-idealities in physical implementations of QKD can be fully practically exploitable, and must be given increased scrutiny if quantum cryptography is to become highly secure.
Gerhardt, Ilja; Liu, Qin; Lamas-linares, Antia; Skaar, Johannes; Scarani, Valerio; Makarov, Vadim & Kurtsiefer, Christian (2011). Experimentally faking the violation of Bell’s inequalities. Physical Review Letters. ISSN 0031-9007. 107(170404) . doi: 10.1103/PhysRevLett.107.170404 Vis sammendrag
Entanglement witnesses such as Bell inequalities are frequently used to prove the non-classicality of a light source and its suitability for further tasks. By demonstrating Bell inequality violations using classical light in common experimental arrangements, we highlight why strict locality and efficiency conditions are not optional, particularly in security-related scenarios.
Grepstad, Jon Olav & Skaar, Johannes (2011). Does evanescent gain exist?, In W. Ross Stone (ed.), Proceedings of the XXXth URSI General Assembly in Istanbul (August 2011). IEEE conference proceedings. ISBN 978-1-4244-5117-3. Artikkel.
Grepstad, Jon Olav & Skaar, Johannes (2011). Total internal reflection and evanescent gain. Optics Express. ISSN 1094-4087. 19(22), s 21404- 21418 . doi: 10.1364/OE.19.021404 Fulltekst i vitenarkiv.
Lydersen, Lars Vincent Van de Wiel; Akhlaghi, Mohsen K.; Majedi, A. Hamed; Skaar, Johannes & Makarov, Vadim (2011). Controlling a superconducting nanowire single-photon detector using tailored bright illumination. New Journal of Physics. ISSN 1367-2630. 13 . doi: 10.1088/1367-2630/13/11/113042 Fulltekst i vitenarkiv.
Lydersen, Lars Vincent Van de Wiel; Jain, Nitin; Wittmann, Christoffer; Marøy, Øystein; Skaar, Johannes; Marquardt, Christoph; Makarov, Vadim & Leuchs, Gerd (2011). Superlinear threshold detectors in quantum cryptography. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 1050-2947. 84 . doi: 10.1103/PhysRevA.84.032320
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim & Skaar, Johannes (2011). Secure gated detection scheme for quantum cryptography. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 1050-2947. 83(3) . doi: 10.1103/PhysRevA.83.032306
Lydersen, Lars Vincent Van de Wiel; Skaar, Johannes & Makarov, Vadim (2011). Tailored bright illumination attack on distributed-phase-reference protocols. Journal of Modern Optics. ISSN 0950-0340. 58(8), s 680- 685 . doi: 10.1080/09500340.2011.565889
Sauge, Sebastien; Lydersen, Lars Vincent Van de Wiel; Anisimov, Andrey; Skaar, Johannes & Makarov, Vadim (2011). Controlling an actively-quenched single photon detector with bright light. Optics Express. ISSN 1094-4087. 19, s 23590- 23600 . doi: 10.1364/OE.19.023590 Fulltekst i vitenarkiv.
Svendsen, Guro Kristin; Weman, Helge & Skaar, Johannes (2011). Model for reflection and transmission matrices of nanowire end facets. Journal of Applied Physics. ISSN 0021-8979. 109(10), s 103101 . doi: 10.1063/1.3583496
Wiechers, Carlos; Lydersen, Lars Vincent Van de Wiel; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes; Marquardt, Christoph; Makarov, Vadim & Leuchs, Gerd (2011). After-gate attack on a quantum cryptosystem. New Journal of Physics. ISSN 1367-2630. 13 . doi: 10.1088/1367-2630/13/1/013043 Fulltekst i vitenarkiv.
Andresen, Marte Pernille Hatlo; Skaldebø, Aleksander Vatn; Haakestad, Magnus Willum; Krogstad, Harald E & Skaar, Johannes (2010). Effect of gain saturation in a gain compensated perfect lens. Journal of the Optical Society of America. B, Optical physics. ISSN 0740-3224. 27(8), s 1610- 1616
Lydersen, Lars Van De Wiel & Skaar, Johannes (2010). SECURITY OF QUANTUM KEY DISTRIBUTION WITH BIT AND BASIS DEPENDENT DETECTOR FLAWS. Quantum information & computation. ISSN 1533-7146. 10(1-2), s 60- 76
Lydersen, Lars Van De Wiel; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes & Makarov, Vadim (2010). Hacking commercial quantum cryptography systems by tailored bright illumination. Nature Photonics. ISSN 1749-4885. 4(10), s 686- 689 . doi: 10.1038/nphoton.2010.214 Vis sammendrag
The peculiar properties of quantum mechanics allow two remote parties to communicate a private, secret key, which is protected from eavesdropping by the laws of physics. So-called quantum key distribution (QKD) implementations always rely on detectors to measure the relevant quantum property of single photons. Here we demonstrate experimentally that the detectors in two commercially available QKD systems can be fully remote-controlled using specially tailored bright illumination. This makes it possible to tracelessly acquire the full secret key; we propose an eavesdropping apparatus built from off-the-shelf components. The loophole is likely to be present in most QKD systems using avalanche photodiodes to detect single photons. We believe that our findings are crucial for strengthening the security of practical QKD, by identifying and patching technological deficiencies.
Lydersen, Lars Vincent Van de Wiel; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes & Makarov, Vadim (2010). Thermal blinding of gated detectors in quantum cryptography. Optics Express. ISSN 1094-4087. 18(26), s 27938- 27954 . doi: 10.1364/OE.18.027938
Marøy, Øystein; Lydersen, Lars Vincent Van de Wiel & Skaar, Johannes (2010). Security of quantum key distribution with arbitrary individual imperfections. Physical Review A. Atomic, Molecular, and Optical Physics (PRA). ISSN 1050-2947. 82(3) . doi: 10.1103/PhysRevA.82.032337
Skaar, Johannes (2010). Causality and its implications for passive and active media, In Electromagnetic Theory (EMTS), 2010 URSI International Symposium on, Berlin, 16-19 Aug 2010. IEEE Press. ISBN 978-1-4244-5154-8. KAPITTEL. s 29 - 32
Skaar, Johannes (2010). Fiber Bragg Gratings: Analysis and Synthesis Techniques, In Andrea Cusano; Antonello Cutolo & Jacques Albert (ed.), Fiber Bragg Grating Sensors: Recent Advancements, Industrial Applications and Market Exploitation. Bentham eBooks. ISBN 978-1-60805-084-0. Chapter 3. s 35 - 52
Haakestad, Magnus Willum & Skaar, Johannes (2009). Slow and fast light in optical fibers using acoustooptic coupling between two co-propagating modes. Proceedings of SPIE, the International Society for Optical Engineering. ISSN 0277-786X. 7226 . doi: 10.1117/12.807548
Haakestad, Magnus Willum & Skaar, Johannes (2009). Slow and fast light in optical fibers using acoustooptic coupling between two co-propagating modes. Optics Express. ISSN 1094-4087. 17(1), s 346- 357
Lind-Johansen, Øyvind; Seip, Kristian & Skaar, Johannes (2009). The perfect lens on a finite bandwidth. Journal of Mathematical Physics. ISSN 0022-2488. 50(1) . doi: 10.1063/1.3068751

Se alle arbeider i Cristin

Nilsen, Fabian Skalleberg & Skaar, Johannes (2020, 24. februar). Østlandssendingen - er det mulig å forsyne seg selv med strøm ved hjelp av spinningsykler og tredemøller?. [Radio]. NRK P1.
Fedorov, Aleksey; Gerhardt, Ilja; Huang, Anqi; Jogenfors, Jonathan; Kurochkin, Yury; Lamas-Linares, Antia; Larsson, Jan-Åke; Leuchs, Gerd; Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim & Skaar, Johannes (2019). Comment on 'Inherent security of phase coding quantum key distribution systems against detector blinding attacks' (2018 Laser Phys. Lett. 15 095203). Laser Physics Letters. ISSN 1612-2011. 16 . doi: 10.1088/1612-202X/aaf22d
Hågenvik, Hans Olaf & Skaar, Johannes (2019). Analysis of active and passive metamaterials.
Jemterud, Torkild; Skaar, Johannes; Eidsvoll, David & Iqbal, Yasmin Sofia (2019, 01. november). Abels tårn. [Radio]. NRK P2.
Risan, Lars & Skaar, Johannes (2019). SENT-kveld på Teknisk museum: Foredrag om kvantedatamaskiner.
Skaar, Johannes (2019, 28. oktober). Intervju av TV2 Nyhetskanalen, kl 0710, om kvantedatamaskiner. [TV]. TV2 Nyhetskanalen.
Skaar, Johannes (2019). Musikk og matematikk.
Dirdal, Christopher Andrew; Hågenvik, Hans Olaf; Haave, Haakon Aamodt & Skaar, Johannes (2018). Higher order multipoles in metamaterial homogenization.
Skaar, Johannes (2018). Energi - uten en tråd.
Skaar, Johannes (2018). Fysikk og musikk.
Skaar, Johannes (2018). Matematikk i musikk.
Andersen, Elise Rønnevig; Bratberg, Øivind; Hellum, Mari Kjos; Hjelle, Ole Petter; Hussein, Bassam; Lie, Anne Helene Kveim; McNicol, John; Raklev, Are; Selboe, Tone; Skaar, Johannes & Stensaker, Inger G. (2017, 31. august). Landets beste forelesere svarer: Slik studerer du mest effektivt. Aftenposten.
Klingenberg, Mathias & Skaar, Johannes (2017, 13. februar). 100 milliarder bilder i sekundet fanger lys som går raskere enn seg selv. [Fagblad]. Teknisk ukeblad.
Mauren, Arnfinn & Skaar, Johannes (2017, 01. januar). Magisk teknologi kan bety farvel til hacking. [Fagblad]. Aftenposten Vitenskap.
Opheim, Aagot & Skaar, Johannes (2017, 11. januar). Vil gi ære, status og høyere lønn til de beste underviserne. Adresseavisen.
Sande, Anniken & Skaar, Johannes (2017, 27. januar). Her og nå: Dagens gjest. [Radio]. NRK P1.
Skaar, Johannes (2017). Musikkens fysikk.
Skaar, Johannes & Tollersrud, Emma (2017, 20. januar). Med lønnsøkning skal underviserne skinne. Morgenbladet.
Stensvold, Tore & Skaar, Johannes (2017, 13. oktober). Norwegian Tech Awards 2017 - WÄRTSILÄ. De lader ferge med 1,2 megawatt effekt - uten fysisk kontakt med fartøyet. [Fagblad]. Teknisk ukeblad.
Sund, Steinar & Skaar, Johannes (2017, 27. september). Snart kan du lade med klærne. [Tidsskrift]. Aftenposten Vitenskap.
Sævik, Bjørnar Torvholm; Folven, Erik; Jahre, Magnus & Skaar, Johannes (2017, 24. februar). Ein æra er omm. [Internett]. nrk.no.
Bakken, Kjersti & Skaar, Johannes (2016, 20. september). Norgesglasset: "Lærer man egentlig noe av forelesninger, eller trenger studentene noe helt annet for å bli flinke?". [Radio]. NRK P1.
Dirdal, Christopher Andrew; Hågenvik, Hans Olaf & Skaar, Johannes (2016). Higher order terms and origin dependence in metamaterial homogenization.
Dirdal, Christopher Andrew; Hågenvik, Hans Olaf & Skaar, Johannes (2016). Permittivity, permeability, and the significance of the electrical quadrupole in metamaterials.
Hågenvik, Hans Olaf; Dirdal, Christopher Andrew & Skaar, Johannes (2016). Homogenization of metamaterials: comparison and analysis.
Indregard, Sigve & Skaar, Johannes (2016, 25. november). Til Mars med mikrobølgeovn. Morgenbladet.
Kleiven, David; Skjønsfjell, Eirik Torbjørn Bakken; Zontone, Federico; Chushkin, Yuriy; Skaar, Johannes & Breiby, Dag Werner (2016). Experimental and Numerical Studies for Improved Coherent Diffraction Phase Retrieval.
Skaar, Johannes (2016). Kortforedrag om musikk og fysikk.
Skaar, Johannes (2016). Magneter, metallrør og usynlighetskapper.
Tollersrud, Emma & Skaar, Johannes (2016, 02. september). «Hvis vi ikke underviser, er det lett å ta elementære ting for gitt.». Morgenbladet.
Dirdal, Christopher Andrew & Skaar, Johannes (2015). Giving Freedom and Physical Meaning to the Effective Parameters of Metamaterials for all Frequencies.
Hågenvik, Hans Olaf & Skaar, Johannes (2015). Laplace-Fourier analysis and instabilities of an active slab.
Jegtvik, Karin & Skaar, Johannes (2015, 02. april). Er du vinneren av påskefjellet?. [Internett]. nrk.no.
Ramsdal, Roar & Skaar, Johannes (2015, 18. mars). Her sendes 10 kilowatt trådløst. [Internett]. Teknisk ukeblad.
Skaar, Johannes (2015). Hva er lys?.
Skaar, Johannes (2015). Maxwells teori og Hertz' eksperiment – grunnlaget for moderne telekommunikasjon ble skapt for 150 år siden.
Andreassen, Katrine; Skaar, Johannes; Løland, Anders & Rolén, Tage (2014, 11. februar). Finn ut om du er en sinke på ski. [Internett]. klikk.no.
Brandslet, Steinar; Skaar, Johannes; Løland, Anders & Rolén, Tage (2014). Hvor fort går du på ski?. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116.
Børringbo, Klaus & Skaar, Johannes (2014, 29. september). Trådløs strøm – snart er den her. Aftenposten.
Dalløkken, Per Erlien; Skaar, Johannes & Samset, Bjørn Hallvard (2014, 01. juli). «Metamaterialer» skal beskytte piloter mot laserangrep fra bakken. [Internett]. Teknisk ukeblad.
Dirdal, Christopher Andrew & Skaar, Johannes (2014). Metamaterial responses beyond the Kramers-Kronig relations.
Dirdal, Christopher Andrew & Skaar, Johannes (2014). Superposing Lorentzian functions towards engineering target responses. The 5th International Conference on Metamaterials, Photonic Crystals and Plasmonics Book of Abstracts.
Dirdal, Christopher Andrew & Skaar, Johannes (2014). Superposing Lorentzian functions towards engineering target responses.
Iversen, Marita Løvmo; Jansrud, Line & Skaar, Johannes (2014, 27. april). Går det an å gjøre noe usynlig? NRK Newton. [TV]. NRK 1.
Schirber, Michael; Bugge, Audun Nystad; Sauge, Sebastien; Ghazali, Aina; Skaar, Johannes; Lydersen, Lars Vincent Van de Wiel & Makarov, Vadim (2014, 18. februar). Synopsis: Cyberattack by Breaking and Entering. [Internett]. APS Physics.
Svendsen, Guro Kristin; Skaar, Johannes; Weman, Helge & Dupertuis, M.-A. (2014). Symmetries and optical transitions of hexagonal quantum dots in GaAs/AlGaAs nanowires.
Brandslet, Steinar; Skaar, Johannes; Løland, Anders & Rolén, Tage (2013, 12. desember). Hvor fort går du på ski?. [Internett]. forsking.no.
Brandslet, Steinar; Skaar, Johannes; Løland, Anders & Rolén, Tage (2013). Hvor fort går du på ski?. Gemini. ISSN 0802-085X. (2), s 6- 7
Flæten, Sigurd Øygarden & Skaar, Johannes (2013, 05. desember). Laser kan bli fremtidens spionkamera. [Internett]. Teknisk ukeblad.
Haugen, Vegard & Skaar, Johannes (2013). Døde av elektrosjokk med iPhone 5 i hånden. VG-Nett.
Haugen, Vegard & Skaar, Johannes (2013, 15. juli). Døde av elektrosjokk med iPhone 5 i hånden. [Internett]. amobil.no.
Lydersen, Lars Vincent Van de Wiel & Skaar, Johannes (2013). Kvantekryptografi. Fra Fysikkens Verden. ISSN 0015-9247. 75(1), s 10
Moe, Enok & Skaar, Johannes (2013). Rockheim forstyrrer flytrafikken på Værnes. Adresseavisen. ISSN 0805-3804.
Skaar, Johannes; Løland, Anders; Rolén, Tage & Kokkegård, Hanne (2013, 26. desember). Vild med tal? Tæl dig frem til, om du er hurtigst. [Internett]. dr.dk.
Bugge, Audun Nystad; Sauge, Sebastien; Ghazali, Aina; Skaar, Johannes; Lydersen, Lars Vincent Van de Wiel & Makarov, Vadim (2012). Laser damage of photodiodes helps the eavesdropper.
Grepstad, Jon Olav; Kaspar, Peter; Johansen, Ib-Rune; Skaar, Johannes; Sudbø, Aasmund & Solgaard, Olav (2012). Optical detection of single biomolecules using photonic-crystal membranes.
Time, Jon Kåre & Skaar, Johannes (2012, 13. september). I bakvendtland der alt går an. Morgenbladet.
Time, Jon Kåre & Skaar, Johannes (2012, 06. september). Trollmannen fra Tyrifjord. Morgenbladet.
Christensen, Arnfinn & Skaar, Johannes (2011, 27. mai). Strøm uten støpsel. [Internett]. forskning.no.
Giæver, Ole Peder; Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 16. august). Norske forskere knekte koden. [Internett]. ABC nyheter.
Grepstad, Jon Olav; Due-Hansen, Jon; Johansen, Ib-Rune; Borch, Morten; Kaspar, Peter; Furuberg, Liv; Skaar, Johannes; Sudbø, Aasmund Sveinung & Solgaard, Olav (2011). Umiddelbar diagnose i 2020.
Grepstad, Jon Olav; Kaspar, Peter; Due-Hansen, Jon; Johansen, Ib-Rune; Borch, Morten; Furuberg, Liv; Skaar, Johannes; Sudbø, Aasmund Sveinung & Solgaard, Olav (2011). System for optical characterization of photonic crystal membranes - designed for biological sensing with single molecule sensitivity.
Grepstad, Jon Olav & Skaar, Johannes (2011). Does evanescent gain exist?.
Jemterud, Torkild & Skaar, Johannes (2011, 04. januar). Verdt å vite: Usynlighetskapper. [Radio]. NRK P2.
Lee, Chris; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2011, 15. november). Researchers show how to break quantum cryptography by faking quantum entanglement. [Internett]. Ars Technica.
Liu, Qin; Gerhardt, Ilja; Makarov, Vadim; Skaar, Johannes; Lamas-linares, Antia; Scarani, Valerio & Kurtsiefer, Christian (2011). Implementation of an attack scheme on a practical QKD system.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 23. juni). Eavesdropper Steals Quantum Crypto Keys. [Internett]. InformationWeek.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 01. august). Eavesdropper demonstrates loophole in secure communications. [Internett]. Photonics Spectra.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 18. juni). First Exploit On Quantum Cryptography Confirmed. [Internett]. Slashdot.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 16. juni). Gjør kvantekryptografi enda sikrere. [Internett]. digi.no.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 19. juni). Hackers pioneros rompen criptosistema cuántico. [Internett]. ALT1040.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 17. juni). Hackers steal quantum code. [Internett]. Physics World.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 14. juni). Kryptografia kwantowa jest nie do złamania?. [Internett]. Gazeta.pl.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 20. juni). Quantum crypto felled by 'Perfect Eavesdropper' exploit. [Internett]. The Register.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 15. august). Scientists crack quantum cryptography. [Internett]. Computing.co.uk.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 13. august). Tricking the perfect code machine. [Internett]. BBC.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 20. juni). Взломана действующая система квантовой криптографии. [Internett]. Компьюлента.
Liu, Qin; Makarov, Vadim & Skaar, Johannes (2011, 22. juni). Лазерная атака. [Internett]. Лента.Ру.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2011). Eavesdropping on quantum cryptography using tailored bright light.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2011). Å knekke den uknekkelige koden.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim & Skaar, Johannes (2011). Comment on "Resilience of gated avalanche photodiodes against bright illumination attacks in quantum cryptography" [Appl. Phys. Lett. 98, 231104 (2011)]. Applied Physics Letters. ISSN 0003-6951. 99(19) . doi: 10.1063/1.3658806
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim & Skaar, Johannes (2011, 08. februar). Hack Me If You Can. Optics & Photonics Focus.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim & Skaar, Johannes (2011). SNSPD's in quantum cryptography.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim & Skaar, Johannes (2011). Superconducting single photon detectors in quantum cryptography.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Skaar, Johannes & Liu, Qin (2011). Hacking quantum cryptography.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Skaar, Johannes & Marøy, Øystein (2011). Bright illumination attacks on QKD.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Skaar, Johannes & Marøy, Øystein (2011). Bright illumination attacks: distributed-phase-reference protocols and countermeasures.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Skaar, Johannes & Marøy, Øystein (2011). Superlinear threshold detectors in quantum cryptography.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Skaar, Johannes & Marøy, Øystein (2011). Weak after-gate attack and proposed secure gated detection scheme.
Lydersen, Lars Vincent Van de Wiel; Skaar, Johannes & Makarov, Vadim (2011). Practical security of quantum cryptography.
Lydersen, Lars Vincent Van de Wiel; Skaar, Johannes; Makarov, Vadim & Liu, Qin (2011). Quantum cryptography and quantum hacking.
Makarov, Vadim; Liu, Qin; Skaar, Johannes & Goodin, Dan (2011, 25. oktober). Uncrackable quantum crypto undermined by new attack. [Internett]. The Register.
Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel; Liu, Qin & Skaar, Johannes (2011). Cracking commercial quantum cryptography.
Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel; Liu, Qin & Skaar, Johannes (2011). Cracking commercial quantum cryptography.
Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel; Liu, Qin; Skaar, Johannes; Gerhardt, Ilja; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Lamas-Linares, Antia & Kurtsiefer, Christian (2011). Cracking commercial quantum cryptography.
Makarov, Vadim; Skaar, Johannes; Lydersen, Lars Vincent Van de Wiel; Knight, Helen & Liu, Qin (2011, 25. oktober). Quantum hackers: Cracking the uncrackable code. [Internett]. New Scientist. Vis sammendrag
Also in print edition of the magazine: vol. 2835, pages 44-47 (2011)
Merali, Zeeya; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2011, 25. november). Lasers illuminate quantum security loophole. [Internett]. Nature News.
Miller, Johanna; Makarov, Vadim; Kurtsiefer, Christian; Liu, Qin & Skaar, Johannes (2011, 01. desember). "Faked states" mimic quantum entanglement. [Internett]. Physics Today. Vis sammendrag
Also in print edition: Physics Today Vol. 64, Issue 12, pages 20-23.
Scharf, Rainer; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2011, 27. oktober). Quantenkryptographie: Bell-Ungleichung ausgetrickst. [Internett]. pro-physik.de.
Skaar, Johannes (2011). Elektromagnetisme.
Voss, David; Makarov, Vadim; Kurtsiefer, Christian; Liu, Qin & Skaar, Johannes (2011, 20. oktober). Synopsis: Eve Fools Alice and Bob. [Internett]. Physics.
Zyga, Lisa; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2011, 08. november). Fake violations of Bell tests reinforce importance of closing loopholes. [Internett]. PhysOrg.com.
Fjelldal, Stian; Skaar, Johannes; Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel & Liu, Qin (2010, 05. november). Hacker på statens regning. VG.
Grepstad, Jon Olav; Johansen, Ib-Rune; Borch, Morten; Furuberg, Liv; Skaar, Johannes; Sudbø, Aasmund Sveinung & Solgaard, Olav (2010). Photonic crystal based biosensing platform for single molecule detection.
Jemterud, Torkild & Skaar, Johannes (2010, 16. desember). Verdt å vite: Illusjoner vha metamaterialer. [Radio]. NRK P2.
Lee, Chris; Lydersen, Lars Vincent Van de Wiel; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes & Makarov, Vadim (2010, 13. desember). Quantum cryptography is secure... except when it's not. [Internett]. Ars Technica.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Liu, Qin; Marøy, Øystein & Skaar, Johannes (2010). QKD and Quantum Hacking.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2010). Breaking the Unbreakable Quantum Key Distribution.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2010). Breaking the Unbreakable Quantum Key Distribution.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2010). Kvantekryptografi og kvantehacking.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim; Liu, Qin & Skaar, Johannes (2010). Quantum Cryptography and Quantum Hacking.
Lydersen, Lars Vincent Van de Wiel; Makarov, Vadim & Skaar, Johannes (2010). Eavesdropping using bright light.
Lydersen, Lars Vincent Van de Wiel; Skaar, Johannes; Makarov, Vadim & Liu, Qin (2010). Breaking the Unbreakable Quantum Key Distribution.
Lydersen, Lars Vincent Van de Wiel; Skaar, Johannes; Makarov, Vadim & Liu, Qin (2010). Practical quantum hacking.
Lydersen, Lars Vincent Van de Wiel; Skaar, Johannes; Makarov, Vadim; Marøy, Øystein & Liu, Qin (2010). Quantum key distribution and quantum hacking.
Lydersen, Lars Vincent Van de Wiel; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes & Makarov, Vadim (2010). Avoiding the blinding attack in QKD reply. Nature Photonics. ISSN 1749-4885. 4(12), s 801- 801 . doi: 10.1038/nphoton.2010.278
Lydersen, Lars Vincent Van de Wiel; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes & Makarov, Vadim (2010). Cracking commercial quantum cryptography.
Lydersen, Lars Vincent Van de Wiel; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Skaar, Johannes & Makarov, Vadim (2010). Hacking commercial quantum cryptography systems by tailored bright illumination.
Makarov, Vadim; Liu, Qin; Lydersen, Lars Van De Wiel; Marøy, Øystein & Skaar, Johannes (2010). Hacking quantum cryptography.
Makarov, Vadim; Lydersen, Lars Van De Wiel; Liu, Qin; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Gerhardt, Ilja; Sauge, Sebastien; Skaar, Johannes; Lamas-Linares, Antia & Kurtsiefer, Christian (2010). Perfect eavesdropping: 100% key, 0% QBER.
Makarov, Vadim; Lydersen, Lars Van De Wiel; Liu, Qin; Wiechers, Carlos; Wittmann, Christoffer; Elser, Dominique; Gerhardt, Ilja; Sauge, Sebastien; Skaar, Johannes; Lamas-Linares, Antia & Kurtsiefer, Christian (2010). Perfect eavesdropping: 100% key, 0% QBER.
Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel; Liu, Qin & Skaar, Johannes (2010). How we cracked commercial quantum cryptography systems.
Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel; Liu, Qin & Skaar, Johannes (2010). How we cracked commercial quantum cryptography systems.
Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel & Skaar, Johannes (2010, 31. august). 挪威发现“无痕截获”量子通信的方法. [Internett]. 新华网.
Simonsen, Eivind Sjøtun; Makarov, Vadim; Lydersen, Lars Van De Wiel & Skaar, Johannes (2010). Quantum key distribution system.
Skaar, Johannes (2010). Causality and its implications for passive and active media.
Skaar, Johannes (2010). Musikkens fysikk.
Skaar, Johannes (2010). TFE4120 Elektromagnetisme: Maxwells likninger.
Skaar, Johannes (2010). Vektoranalyse - TFE4120 Elektromagnetisme.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 30. august). Hackers Eavesdrop On Quantum Crypto With Lasers. [Internett]. slashdot.org.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 29. august). Hackers blind quantum cryptographers. [Internett]. nature.com/news.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 30. august). Hardware Hack Busts Quantum Encryption. [Internett]. International Business Times.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 01. september). Hardware hackers defeat quantum crypto. [Internett]. The Register.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 02. september). Knekte «hackersikker» kryptering. [Internett]. adressa.no.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 02. september). Knekte superkryptering. [Internett]. Elektronikknett.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 02. september). NTNU-forskere klarte å knekke superkryptering. [Internett]. Universitetsavisa.no.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 01. september). NTNU-forskere knekte superkryptering. [Internett]. Teknisk Ukeblad (tu.no).
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 08. september). Quantum Cryptography Breached With Lasers. [Internett]. Information Week.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 30. august). Quantum Hackers Use Lasers to Crack Powerful Encryption Without Leaving a Trace. [Internett]. Popsci.com.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 02. september). Quantum Hacking cracks quantum crypto. [Internett]. TechRepublic.com.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 01. september). Quantum crypto detectors cracked by researchers. [Internett]. ZDNet UK.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 10. september). Quantum crypto products cracked by researchers. [Internett]. Government Computer News.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 05. september). Quantum key distribution in superposition of "insecure" and "unneeded". [Internett]. ars technica.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 31. august). Quantum key security 'blinded' by new attack. [Internett]. techworld.com.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 31. august). Researchers Find Quantum Encryption Hack. [Internett]. eweek.com.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 31. august). Scientists uncover quantum encryption system weakness. [Internett]. PC pro.
Skaar, Johannes; Makarov, Vadim & Lydersen, Lars Vincent Van de Wiel (2010, 02. september). Successful Attack Against a Quantum Cryptography System. [Internett]. schneier.com.
Skaar, Johannes; Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel & Liu, Qin (2010, 03. september). Lager hackemat av kryptering. [Internett]. forskning.no.
Skaar, Johannes; Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel & Liu, Qin (2010, 08. september). Lager hackemat av kryptering. Gemini.
Skaar, Johannes; Makarov, Vadim; Lydersen, Lars Vincent Van de Wiel & Liu, Qin (2010, 02. september). Schrödinger's cat and mouse. [Internett]. The Economist.
Svendsen, Guro Kristin; Weman, Helge & Skaar, Johannes (2010). Modelling of reflection properties of nanowire lasers.
Wiechers, Carlos; Lydersen, Lars Vincent Van de Wiel; Jain, Nitin; Wittmann, Christoffer; Elser, Dominique; Makarov, Vadim; Marquardt, Christoph; Lucio, Jose; Skaar, Johannes & Leuchs, Gerd (2010). Improving quantum key distribution systems by quantum hacking tests.
Marøy, Øystein; Skaar, Johannes & Lydersen, Lars Van De Wiel (2009). Security of Quantum Key Distribution with Imperfect Equipment.
Skaar, Johannes (2009). Kvantekryptografi, kvantehacking og sikkerhet.
Skaar, Johannes (2009). Quantum key distribution and quantum hacking.
Skaar, Johannes (2009). Quantum key distribution and quantum hacking.

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Publisert 3. sep. 2019 08:19 - Sist endret 3. mars 2021 15:16

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Teoretisk fysikk