Online Seminar: Dr Chris Jackson, UNM

A scalable fermion measurement: Generalised coherent states and phase space geometry

Speaker: Dr Chris Jackson, Center for Quantum Information and Control and QSI

Host: A/Prof. Chris Ferrie, Centre for Quantum Software and Information

Abstract:
Fermion systems have a Hilbert space dimension that scales exponentially in the number of modes. Standard tomography thus says that to completely measure an unknown state would require the measurement of exponentially many observables. However, if the parity of a fermion state is known, then there exists a nonadaptive, tomographically complete continuous measurement which only requires the isotropic measurement of quadratically many observables. 

The effects of the corresponding POVM are the well known superconducting Bardeen-Cooper-Schrieffer (BCS) coherent states. The BCS coherent states define a manifold which can be used as a phase space to represent fermion quantum information. In this talk, I will introduce the BCS-coherent state POVM, explain the isotropic measurement which implements it, and discuss the geometry of the corresponding phase space.

Watch: Chris Jackson's seminar on QSI's YouTube channel