Death of entanglement and non-locality in a superconducting qubit-field entangled state in a thermal reservoir

Abstract

The analytical description of a superconducting qubit strongly coupled to a resonator with a thermal reservoir is given. Link between nonlocality and entanglement is investigated, they can be manipulated and controlled by any change in the thermal reservoir parameters. According to the Peres conjecture: if the state has negative partial transposition, then the violation of Bell's inequality occurs. Under the effect of thermal noise, the negative partial transposition is transformed to positive. Therefore, the state shows the phenomenon of sudden death of both entanglement and nonlocality.