Quantum simulation of the spin-boson model with a microwave circuit

TL;DR

This paper proposes a superconducting circuit approach to simulate the spin-boson model, enabling exploration of strong coupling regimes and complex dynamics that are difficult for classical simulations.

Contribution

It introduces a method to implement a continuous spectral bath using microwave resonators coupled to a superconducting qubit for quantum simulation.

Findings

Demonstrates coupling of a qubit to multiple resonators simulating a spectral bath

Proposes microwave drive schemes to reach strong-coupling regimes

Shows how to probe spin relaxation dynamics with circuit QED techniques

Abstract

We consider superconducting circuits for the purpose of simulating the spin-boson model. The spin-boson model consists of a single two-level system coupled to bosonic modes. In most cases, the model is considered in a limit where the bosonic modes are sufficiently dense to form a continuous spectral bath. A very well known case is the ohmic bath, where the density of states grows linearly with the frequency. In the limit of weak coupling or large temperature, this problem can be solved numerically. If the coupling is strong, the bosonic modes can become sufficiently excited to make a classical simulation impossible. Here, we discuss how a quantum simulation of this problem can be performed by coupling a superconducting qubit to a set of microwave resonators. We demonstrate a possible implementation of a continuous spectral bath with individual bath resonators coupling strongly to the qubit. Applying a microwave drive scheme potentially allows us to access the strong-coupling regime of the spin-boson model. We discuss how the resulting spin relaxation dynamics with different initialization conditions can be probed by standard qubit-readout techniques from circuit quantum electrodynamics.