Fast, Accurate, and Local Temperature Control Using Qubits

TL;DR

This paper proposes a method for rapid, precise, and localized temperature control in quantum systems using qubits, enabling effective heating or cooling at subkelvin temperatures on nanosecond timescales.

Contribution

It introduces a novel approach for temperature regulation in quantum systems using a small number of qubits, combining heat flow control with work done on the qubits.

Findings

Significant cooling of quantum systems at subkelvin temperatures achieved.

Temperature control can be performed on nanosecond timescales.

Method is compatible with existing superconducting and spin qubit technologies.

Abstract

Many quantum technologies, including quantum computers, quantum heat engines, and quantum sensors, rely on operating conditions in the subkelvin regime. It is therefore desirable to develop practical tools and methods for the precise control of the temperature in nanoscale quantum systems. Here, we present a proposal for fast, accurate, and local temperature control using qubits, which regulate the flow of heat between a quantum system and its thermal environment. The qubits are kept in a thermal state with a temperature that is controlled in an interplay between work done on the qubits by changing their energy splittings and the flow of heat between the qubits and the environment. Using only a few qubits, it is possible to control the thermal environment of another quantum system, which can be heated or cooled by the qubits. As an example, we show how a quantum system at subkelvin temperatures can be significantly and accurately cooled on a nanosecond timescale. Our proposal can potentially be realized with superconducting flux qubits, charge qubits, or spin qubits, which can now be fabricated and manipulated with exquisite control.