Probing quantum anomalous heat flow using mid-circuit measurements

TL;DR

This paper demonstrates quantum anomalous heat flow between qubits using mid-circuit measurements on quantum computers, revealing quantum correlations and the impact of measurement-induced disturbances on heat flow bounds.

Contribution

It presents the first experimental observation of quantum anomalous heat flow with mid-circuit measurements, highlighting their role in violating classical heat bounds and modeling associated noise effects.

Findings

Violation of semi-classical heat flow bounds

Detection of negativities in Kirkwood-Dirac quasiprobability

Measurement-induced disturbances affecting heat flow

Abstract

Gate-based quantum computers are an innovative tool for experimentally studying the core principles of quantum mechanics. This work presents the first observation of quantum anomalous heat flow between two qubits and investigates the role of mid-circuit measurements in this context. Using mid-circuit measurements, we designed quantum circuits that violate the semi-classical heat flow bound, witnessing negativities in the underlying Kirkwood-Dirac quasiprobability distribution, which indicates the presence of quantum correlations between the subsystems. Mid-circuit measurements, crucial for probing qubits during the experiment, enabled these observations but also introduced disturbances, such as energy leakage, leading to deviations from theoretical predictions. We modeled these noise effects, providing insight into the limitations of current mid-circuit measurement techniques.