TILMA, T. ... et al, 2016. Wigner functions for arbitrary quantum systems. Physical Review Letters, 117 (18), 180401.
The possibility of constructing a complete, continuous Wigner function for any quantum system has been a subject of investigation for over 50 years. A key system that has served to illustrate the difficulties of this problem has been an ensemble of spins. While numerous attempts have come close to generating a complete Wigner phase-space description for such a system, each has either been artificial in its construction or restricted in its applications. Here we present a general method of constructing Wigner functions that can be used to fully describe quantum spin systems of any
dimension or ensemble size.
This paper was accepted for publication in the journal Physical Review Letters and the definitive published version is available at https://doi.org/10.1103/PhysRevLett.117.180401.
MEXT Grant-in-Aid for Scientific Research on Innovative Areas "Science of hybrid quantum systems" Grant Number 15H05870 and JSPS KAKENHI Grant No. 25220601.