Observation of strong and weak thermalization in a superconducting\n quantum processor

Abstract

We experimentally study the ergodic dynamics of a 1D array of 12\nsuperconducting qubits with a transverse field, and identify the regimes of\nstrong and weak thermalization with different initial states. We observe\nconvergence of the local observable to its thermal expectation value in the\nstrong-thermalizaion regime. For weak thermalization, the dynamics of local\nobservable exhibits an oscillation around the thermal value, which can only be\nattained by the time average. We also demonstrate that the entanglement entropy\nand concurrence can characterize the regimes of strong and weak thermalization.\nOur work provides an essential step towards a generic understanding of\nthermalization in quantum systems.\n