Measurement of work and heat in the classical and quantum regimes

TL;DR

This paper experimentally characterizes work, heat, and energy variations in a quantum system using IBMQ, revealing the transition from quantum to classical behavior as environment coupling increases.

Contribution

It provides a comprehensive experimental method to measure quantum thermodynamic quantities and demonstrates the quantum-to-classical transition in energy exchange processes.

Findings

Successful measurement of work, heat, and energy variations in a quantum system.

Observation of reduced quantum features with increased environment coupling.

Use of quasi-probability distributions to recover thermodynamic averages.

Abstract

Despite the increasing interest, the research field which studies the concepts of work and heat at quantum level has suffered from two main drawbacks: first, the difficulty to properly define and measure the work, heat and internal energy variation in a quantum system and, second, the lack of experiments. Here, we report a full characterization of the dissipated heat, work and internal energy variation in a two-level quantum system interacting with an engineered environment. We use the IBMQ quantum computer to implement the driven system's dynamics in a dissipative environment. The experimental data allow us to construct quasi-probability distribution functions from which we recover the correct averages of work, heat and internal energy variation in the dissipative processes. Interestingly, by increasing the environment coupling strength, we observe a reduction of the pure quantum features of the energy exchange processes that we interpret as the emergence of the classical limit. This makes the present approach a privileged tool to study, understand and exploit quantum effects in energy exchanges.