DC current generation and power feature in strongly driven Floquet-Bloch systems

We study the DC current generation in a periodically driven Bloch system connected to heat bath. Under relaxation time approximation, density matrix for such is obtained, which related two equilibria: Floquet quasiequilibrium where diagonal under Floquet-Bloch eigenbasis and an instantaneous thermal equilibrium. Then, responses their power features, i.e., input behavior, are discussed unified manner, reveals that there exist intrinsic extrinsic correction. Remarkably, part consumes no energy corresponds quasiequilibrium, while needs sustained originates from shift between equilibrium ensembles. further investigate role of external driving field strength finding large currents can be generated relatively strong but not too field.