A MODIFIED MOYAL REPRESENTATION AND THE PANCHARATNAM PHASE OF TWO-LEVEL SYSTEMS
Ling Li, Bo‐Zang Li · International Journal of Modern Physics B · 2002
By including a pre-phase-factor, the Moyal representation for the spin-1/2 (or two-level) system is modified. Such a modification is necessary for describing completely the quantum evolution and calculating exactly the quantum phase. In our modified Moyal representation (MMR) the geometrical expression of the most general quantum phase, i.e., the Pancharatnam phase, is deduced in a much simpler way and without the restriction of cyclic evolution. Two simple examples of application of the MMR are given.