Cooling a quantum circuit via coupling to a multiqubit system

TL;DR

This paper explores how coupling a quantum LC circuit with an ensemble of artificial qubits can effectively cool the circuit below thermal background levels, with efficiency influenced by qubit interactions and size.

Contribution

It demonstrates the cooling effects of a multiqubit system on a quantum circuit and compares independent versus collective qubit interactions for efficiency and speed.

Findings

Effective cooling below thermal background achieved.

Larger samples improve cooling efficiency for independent qubits.

Collective interactions lead to faster cooling processes.

Abstract

The cooling effects of a quantum LC circuit coupled inductively with an ensemble of artificial qubits are investigated. The particles may decay independently or collectively through their interaction with the environmental vacuum electromagnetic field reservoir. For appropriate bath temperatures and the resonator's quality factors, we demonstrate an effective cooling well below the thermal background. In particular, we found that for larger samples the cooling efficiency is better for independent qubits. However, the cooling process can be faster for collectively interacting particles.