Liu, R., Chen, Y., Jiang, M., Yang, X., Wu, Z., Li, Y., Yuan, H., Peng, X., and Du, J. npj Quantum Inf 7, 170 (2021)
https://www.nature.com/articles/s41534-021-00507-x
Abstract
Critical quantum metrology, which exploits quantum critical systems as probes to estimate a physical parameter, has gained increasing attention recently. However, the critical quantum metrology with a continuous quantum phase transition (QPT) is experimentally challenging since a continuous QPT only occurs at the thermodynamic limit. Here, we propose an adiabatic scheme on a perturbed Ising spin model with a first-order QPT. By introducing a small transverse magnetic field, we can not only encode an unknown parameter in the ground state but also tune the energy gap to control the evolution time of the adiabatic passage. Moreover, we experimentally implement the critical quantum metrology scheme using nuclear magnetic resonance techniques and show that at the critical point the precision achieves the Heisenberg scaling as 1/T. As a theoretical proposal and experimental implementation of the adiabatic scheme of critical quantum metrology and its advantages of easy implementation, inherent robustness against decays and tunable energy gap, our adiabatic scheme is promising for exploring potential applications of critical quantum metrology on various physical systems.
If you would like to prepare for this, I attach Morten's notes and Jupyter Notebook from last week, as well as the paper. Please feel free to come if you have not had time to look at this as well however.
About the qGAP meeting series
Welcome to qGAP, our seminar series on Quantum Physics and Quantum Technology.
The series of seminars/lectures are meant to cover broadly activities at UiO and elsewhere related to quantum physics and technologies, mainly from a theoretical perspective, though we also welcome experimental talks.
We aim at having regular seminars, discussions of recent articles, presentations by master and PhD students and more. We aim for this series to be a combination of research talks and journal clubs.
Educational topics are also most welcome.
Please feel free to suggest speakers, yourself included!
Get in touch with Gunnar Lange to suggest a speaker or if you would like to be included in the mailing list.
All are welcome!
Upcoming:
14. March - Morten Hjorth-Jensen (UiO/Fysikk)
28. March - Franz Georg Fuchs (Sintef/UiO Matematikk)
4. April - Alexander Müller-Hermes (UiO Matematikk)
11. April - Shaukat Ali (Simula)
25. April Kristian Wold (OsloMet) i qGap