Papers
Topics
Authors
Recent
Gemini 2.5 Flash
Gemini 2.5 Flash
149 tokens/sec
GPT-4o
9 tokens/sec
Gemini 2.5 Pro Pro
47 tokens/sec
o3 Pro
4 tokens/sec
GPT-4.1 Pro
38 tokens/sec
DeepSeek R1 via Azure Pro
28 tokens/sec
2000 character limit reached

Near-ultrastrong nonlinear light-matter coupling in superconducting circuits (2404.19199v2)

Published 30 Apr 2024 in quant-ph

Abstract: The interaction between an atom and an electromagnetic mode of a resonator is of both fundamental interest and is ubiquitous in quantum technologies. Most prior work studies a linear light-matter coupling of the form $g \widehat{\sigma}x (\widehat{a} + \widehat{a}\dagger)$, where $g$ measured relative to photonic ($\omega_a$) and atomic ($\omega_b$) mode frequencies can reach the ultrastrong regime ($g/\omega{a}!>!10{-1}$). In contrast, a nonlinear light-matter coupling of the form $\frac{\chi}{2} \widehat{\sigma}z \widehat{a}\dagger \widehat{a}$ has the advantage of commuting with the atomic $\widehat{\sigma}_z$ and photonic $\widehat{a}\dagger\widehat{a}$ Hamiltonian, allowing for fundamental operations such as quantum-non-demolition measurement. However, due to the perturbative nature of nonlinear coupling, the state-of-the-art $\chi/\text{max}(\omega_a, \omega_b)$ is limited to $!<!10{-2}$. Here, we use a superconducting circuit architecture featuring a quarton coupler to experimentally demonstrate, for the first time, a near-ultrastrong $\chi/\text{max}(\omega_a, \omega_b)= (4.852\pm0.006)\times10{-2}$ nonlinear coupling of a superconducting artificial atom and a nearly-linear resonator. We also show signatures of light-light nonlinear coupling ($\chi\widehat{a}\dagger\widehat{a}\widehat{b}\dagger\widehat{b}$), and $\chi/2\pi = 580.3 \pm 0.4 $ MHz matter-matter nonlinear coupling ($\frac{\chi}{4}\widehat{\sigma}{z,a}\widehat{\sigma}_{z,b}$) which represents the largest reported $ZZ$ interaction between two coherent qubits. Such advances in the nonlinear coupling strength of light, matter modes enable new physical regimes and could lead to applications such as orders of magnitude faster qubit readout and gates.

Citations (1)

Summary

We haven't generated a summary for this paper yet.