Decoherence predictions in a superconducting quantum processor using the steepest-entropy-ascent quantum thermodynamics framework

The current stage of quantum computing technology, called noisy intermediate-scale quantum technology, is characterized by large errors that prohibit it from being used for real applications. In these devices, decoherence, one of the main sources of error, is generally modeled by Markovian master equations such as the Lindblad master equation. In this paper, the decoherence phenomena are addressed from the perspective of the steepestentropy-ascent quantum thermodynamics framework in which the noise is in part seen as internal to the system. The framework is as well used to describe changes in the energy associated with environmental interactions. Three scenarios, an inversion recovery demonstration, a Ramsey demonstration, and a two-qubit entanglementdisentanglement demonstration, are used to demonstrate the applicability of this framework, which provides good results relative to the demonstrations and the Lindblad equation; it does so, however, from a different perspective as to the cause of the decoherence. These demonstrations are conducted on the IBM superconducting quantum device ibmq_bogota.