Qubit Noise Sensing via Induced Photon Loss in a Superconducting Cavity

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Kahn, Nitzan, Garti, Dror, Goldblatt, Uri, Joshi, Lalit M., Lafont, Fabien, Rosenblum, Serge
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913017902399488
author Kahn, Nitzan
Garti, Dror
Goldblatt, Uri
Joshi, Lalit M.
Lafont, Fabien
Rosenblum, Serge
author_facet Kahn, Nitzan
Garti, Dror
Goldblatt, Uri
Joshi, Lalit M.
Lafont, Fabien
Rosenblum, Serge
contents Characterizing noise in superconducting qubits is essential for improving coherence and gate performance. Conventional noise-sensing methods typically use the qubit itself as the sensor, which limits both accessible bandwidth and applicability during driven operation. Here, we demonstrate a method for measuring qubit frequency noise by converting it into photon loss in a coupled high-Q superconducting cavity. We use repeated mid-circuit qubit measurements with post-selection to separate this induced loss from intrinsic cavity decay. We validate the protocol using injected noise and show that the extracted loss scales as expected with the applied noise strength. Without added noise, we place an upper bound of $5\times10^3\,\mathrm{Hz}^2/\,\mathrm{Hz}$ on the qubit frequency-noise power spectral density at 508 MHz. The protocol opens access to a higher-frequency spectral window than standard qubit-based spectroscopy and may enable noise characterization during strong driving.
format Preprint
id arxiv_https___arxiv_org_abs_2603_06848
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Qubit Noise Sensing via Induced Photon Loss in a Superconducting Cavity
Kahn, Nitzan
Garti, Dror
Goldblatt, Uri
Joshi, Lalit M.
Lafont, Fabien
Rosenblum, Serge
Quantum Physics
Characterizing noise in superconducting qubits is essential for improving coherence and gate performance. Conventional noise-sensing methods typically use the qubit itself as the sensor, which limits both accessible bandwidth and applicability during driven operation. Here, we demonstrate a method for measuring qubit frequency noise by converting it into photon loss in a coupled high-Q superconducting cavity. We use repeated mid-circuit qubit measurements with post-selection to separate this induced loss from intrinsic cavity decay. We validate the protocol using injected noise and show that the extracted loss scales as expected with the applied noise strength. Without added noise, we place an upper bound of $5\times10^3\,\mathrm{Hz}^2/\,\mathrm{Hz}$ on the qubit frequency-noise power spectral density at 508 MHz. The protocol opens access to a higher-frequency spectral window than standard qubit-based spectroscopy and may enable noise characterization during strong driving.
title Qubit Noise Sensing via Induced Photon Loss in a Superconducting Cavity
topic Quantum Physics
url https://arxiv.org/abs/2603.06848