Circuit complexity for generalised coherent states in thermal field dynamics

Understand

In this work, we study the circuit complexity for generalized coherent states in thermal systems by adopting the covariance matrix approach.

• We focus on the coherent thermal (CT) state, which is non-Gaussian and has a nonvanishing one-point function.
• We find that even though the CT state cannot be fully determined by the symmetric two-point function, the circuit complexity can still be computed in the framework of the covariance matrix formalism by properly enlarging the covariance matrix.
• Now the group generated by the unitary is the semiproduct of translation and the symplectic group.