## Video URL

https://pirsa.org/24050070# s-ordered phase-space correspondences, fermions, and negativities

### APA

Dangniam, N. (2024). s-ordered phase-space correspondences, fermions, and negativities. Perimeter Institute for Theoretical Physics. https://pirsa.org/24050070

### MLA

Dangniam, Ninnat. s-ordered phase-space correspondences, fermions, and negativities. Perimeter Institute for Theoretical Physics, May. 09, 2024, https://pirsa.org/24050070

### BibTex

@misc{ scivideos_PIRSA:24050070, doi = {10.48660/24050070}, url = {https://pirsa.org/24050070}, author = {Dangniam, Ninnat}, keywords = {Quantum Foundations}, language = {en}, title = {s-ordered phase-space correspondences, fermions, and negativities}, publisher = {Perimeter Institute for Theoretical Physics}, year = {2024}, month = {may}, note = {PIRSA:24050070 see, \url{https://scivideos.org/pirsa/24050070}} }

Ninnat Dangniam Naresuan University

**Source Repository**PIRSA

**Collection**

**Talk Type**Scientific Series

**Subject**

## Abstract

For continuous-variable systems, the negativities in the s-parametrized family of quasi-probability representations on a classical phase space establish a sort of hierarchy of non-classility measures. The coherent states, by design, display no negativity for any value of -1≤s≤1, meaning that sampling from the quantum probability distribution resulting from any measurement of a coherent state can be classically simulated, placing the coherent states as the most classical states according to this particular choice of phase space.

In this talk, I will describe how to construct s-ordered quasi-probability representations for finite-dimensional quantum systems when the phase space is equipped with more general group symmetries, focusing on the fermionic SO(2n) symmetry. Along the way, I will comment on an obstruction to an analogue of Hudson's theorem, namely that the only pure states that have positive s=0 Wigner functions are Gaussian states, and a possible remedy by giving up linearity in the phase-space correspondence.

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