Leggett-Garg Inequality for a Two-Level System under Decoherence

Abstract

We consider a macroscopic quantum system subjected to an asymmetric double-well potential in a harmonic environment. By using a time-dependent approach, we calculate tunnelling probabilities for the system which contain oscillation effects. To show how one can decide between quantum mechanics and the implications of macrorealism assumptions, a given form of Leggett-Garg inequality is considered. The violation of this inequality occurs for a broader range of the system-environment interactions, compared to previous results obtained for two-level systems. Assuming that the coupling strength between the system and the environment can be controlled with time, one can see the violation even for strong decoherence effects. We also investigate the variation of the tilt/tunnelling parameters on the violation of Leggett-Garg inequality.