Delta på prøveforelesning - 20. september kl. 10:15 (rom 402, Institutt for teknologisystemer)
"Foundations of entanglement beyond Bell's theorem".
Delta på prøveforelsningen via Zoom
Meeting ID: 663 4831 6299
Passcode: 628411
Delta på disputasen via Zoom
Meeting ID: 688 2490 4557
Passcode: 219845
Kreeringssammendrag
Elementærpartikler i fysikken lar oss forutsi eksperimenter med svært høy nøyaktighet, men disse partiklene kan ikke lokaliseres i tid og rom. Doktoranden utvikler nye metoder for å beskrive lokaliserte partikkeltilstander innen kvantefeltteori, med spesielt fokus på lys.
Hovedfunn
Photons and other fundamental particles in physics allow us to predict many phenomena in nature with very high accuracy. However, a fundamental limitation of these particle states is that they cannot be localized in space and time, meaning that they cannot describe any signal generated on demand.
In this work we analyze the issue of particle localization in quantum field theory. To formalize what it means for a relativistic particle to be localized, we take an operational approach based on expectation values of local measurements. In this framework it is clear that single photons cannot represent any causal signal, since their energy density is nonzero for all space.
To solve this problem, we introduce a new type of optical state that is localized while simultaneously being close to a single photon in many realizable situations. This new state may represent a non-classical signal generated on demand in quantum field theory.
Furthermore, we establish constraints on the maximum possible fidelity between any localized state and a single photon. The results show that any ultrafast optical signal produced on demand must inevitably contain substantial multiphoton components! These methods also make it possible to demonstrate causality for the much-debated phenomenon of single-photon tunneling.
Leder av disputas
Prof., PhD Cecilie Rolstad Denby, Universitetet i Oslo
Bedømmelseskomité
1. Opponent: Prof., PhD Pieter Kok, University of Sheffield
2. Opponent: Postdoc, PhD Thiago Lucena de Macedo Guedes, Forschungszentrum Jülich
Komitéleder: Prof., PhD Torbjørn Skauli, Universitetet i Oslo
Veiledere
Hovedveileder: Prof., PhD Johannes Skaar, Universitetet i Oslo
Kontaktinformasjon til kandidat
E-post: jangulla93@gmail.com
Mobil nr: +47 90646862
For mer informasjon
PhD-koordinator: Yvonne Baade