Experimental characterization of the energetics of quantum logic gates

V Cimini,M Barbieri,M Paternostro,M Sbroscia,F Caruso,I Gianani,S Gherardini,L Buffoni

doi:10.1038/s41534-020-00325-7

Abstract

We characterize the energetic footprint of a two-qubit quantum gate from the perspective of non-equilibrium quantum thermodynamics. We experimentally reconstruct the statistics of energy and entropy fluctuations following the implementation of a controlled-unitary gate, linking them to the performance of the gate itself and the phenomenology of Landauer’s principle at the single-quantum level. Our work thus addresses the energetic cost of operating quantum circuits, a problem that is crucial for the grounding of the upcoming quantum technologies.

Highlights

Thermodynamics was developed in the nineteenth century to improve the efficiency of steam engines
Despite the significant progress made towards the implementation of prototype quantum devices able to process an increasing amount of information in a reliable and reproducible manner[1,3], little work has been devoted to the characterization of the energetic footprint of such potentially disruptive quantum technologies[4]
The challenge in this respect is to make use of the emerging field of quantum thermodynamics, which aims at establishing a framework for the thermodynamics of quantum processes and systems, to design energy-efficient quantum machines[9,10,11,12] possibly able to outperform their classical counterparts[3], or benchmark the performance of quantum devices from a thermodynamic perspective, as recently done for the interesting case of quantum annealears[13,14]

Summary

INTRODUCTION

Thermodynamics was developed in the nineteenth century to improve the efficiency of steam engines. Despite the significant progress made towards the implementation of prototype quantum devices able to process an increasing amount of information in a reliable and reproducible manner[1,3], little work has been devoted to the characterization of the energetic footprint of such potentially disruptive quantum technologies[4]. This is a crucial point to address: only by ensuring that the energy consumption associated with the performance of quantum information processing[5,6] scales favorably with the size of a quantum processor, would the craved quantum technologies embody a credible alternative to CMOS-.

RESULTS

Cimini et al 2

METHODS