The first journal club this Fall will be led by Kim Graatrud, who is currently writing his MSc thesis with yours truly.
Keywords: Parameter Estimation, Quantum Fisher Information, Kraus Operators, Probe-States, Noise Channels
Abstract
Quantum metrology studies how quantum mechanical properties such as entanglement and squeezing can improve measurement precision beyond classical limits. Classical states, such as product states, saturate the Shot Noise Limit (SNL), with precision scaling as 1/√N in the number of qubits N. Entangled states, such as Greenberger–Horne–Zeilinger (GHZ) states, saturate the Heisenberg Limit (HL), scaling as 1/N, a quadratic improvement over the classical case. However, GHZ states are known to have a short optimal probing time under noise, limiting the number of measurements available for a good estimate. This motivates the search for alternative probe states.
Koczor et al. (2020) propose a variational framework for finding such states. This talk presents the theory, methodology, and key findings of the paper. Aimed at first-year master's students, it will review any mathematical and physical concepts beyond a standard quantum mechanics course before diving into the paper itself.
If you would like to read the paper beforehand, you may find it at:
https://iopscience.iop.org/article/10.1088/1367-2630/ab965e
About the qGAP seminar series
This term, qGap will consist of journal-club style talks discussing interesting papers in quantum science and technology.
We aim to have a biweekly research seminar, with various people presenting research results, or discussing papers in a journal club style.
Ideally, everyone would have read the weekly reading before coming to the seminar, as they will be structured as a discussion rather than a lecture. We particularly encourage Master's students to come.
The seminars are at 14.15 in the CCSE seminar room (4th floor Physics building, East Wing), as per usual
If you have something you would like to present (whether own research or a journal-club style talk), please do not hesitate to get in touch!
A Zoom link for the seminar is available from:
Contact: Gunnar Lange - Postdoctoral Fellow, University of Oslo