Readout of a solid state spin ensemble at the projection noise limit

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Maier, Rouven, Ho, Cheng-I, Denisenko, Andrej, Davydova, Marina, Knittel, Peter, Wrachtrup, Jörg, Vorobyov, Vadim
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910196962426880
author Maier, Rouven
Ho, Cheng-I
Denisenko, Andrej
Davydova, Marina
Knittel, Peter
Wrachtrup, Jörg
Vorobyov, Vadim
author_facet Maier, Rouven
Ho, Cheng-I
Denisenko, Andrej
Davydova, Marina
Knittel, Peter
Wrachtrup, Jörg
Vorobyov, Vadim
contents Spin ensembles are central to quantum science, from frequency standards and fundamental physics searches to magnetic resonance spectroscopy and quantum sensing. Their performance is ultimately constrained by spin projection noise, yet solid-state implementations have so far been limited by much larger photon shot noise. Here we demonstrate a direct, quantum non-demolition readout of a mesoscopic ensemble of nitrogen-vacancy (NV) centers in diamond that surpasses the photon shot-noise limit and approaches the intrinsic spin projection noise. By stabilizing the $^{14}$N nuclear spin bath at high magnetic fields and employing repetitive nuclear-assisted spin readout, we achieve a noise reduction of 3.8 dB below the thermal projection noise level. This enables direct access to the intrinsic fluctuations of the spin ensemble, allowing us to directly observe the signatures of correlated spin states. Our results establish projection noise-limited readout as a practical tool for solid-state quantum sensors, opening pathways to quantum-enhanced metrology, direct detection of many-body correlations, and the implementation of spin squeezing in mesoscopic solid-state ensembles.
format Preprint
id arxiv_https___arxiv_org_abs_2509_11854
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Readout of a solid state spin ensemble at the projection noise limit
Maier, Rouven
Ho, Cheng-I
Denisenko, Andrej
Davydova, Marina
Knittel, Peter
Wrachtrup, Jörg
Vorobyov, Vadim
Quantum Physics
Mesoscale and Nanoscale Physics
Spin ensembles are central to quantum science, from frequency standards and fundamental physics searches to magnetic resonance spectroscopy and quantum sensing. Their performance is ultimately constrained by spin projection noise, yet solid-state implementations have so far been limited by much larger photon shot noise. Here we demonstrate a direct, quantum non-demolition readout of a mesoscopic ensemble of nitrogen-vacancy (NV) centers in diamond that surpasses the photon shot-noise limit and approaches the intrinsic spin projection noise. By stabilizing the $^{14}$N nuclear spin bath at high magnetic fields and employing repetitive nuclear-assisted spin readout, we achieve a noise reduction of 3.8 dB below the thermal projection noise level. This enables direct access to the intrinsic fluctuations of the spin ensemble, allowing us to directly observe the signatures of correlated spin states. Our results establish projection noise-limited readout as a practical tool for solid-state quantum sensors, opening pathways to quantum-enhanced metrology, direct detection of many-body correlations, and the implementation of spin squeezing in mesoscopic solid-state ensembles.
title Readout of a solid state spin ensemble at the projection noise limit
topic Quantum Physics
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2509.11854