Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Materials for Quantum Technology

Nonlinear collective-spin dynamics for quantum-enhanced sensing in solid-state platforms

Le Bin Ho

Published Oct 7, 2026• 0 citations
Publisher

Abstract

Abstract Collective spin systems in solid-state materials are promising platforms for quantum-enhanced sensing. In systems such as nitrogen-vacancy centers in diamond, donor spins in silicon, and magnetic materials, interactions among many spins can generate collective quantum correlations that improve measurement precision beyond the standard quantum limit. This tutorial develops an intuitive, materials-oriented framework for understanding these effects through nonlinear collective-spin dynamics. We show how nonlinear interactions reshape collective spin states in phase space, redistribute quantum fluctuations, and generate metrologically useful states such as spin-squeezed and entangled states. We then connect these ideal collective dynamics to microscopic interactions and realistic solid-state systems, discussing how interaction strength, disorder, decoherence, and experimental control affect sensing performance. Different platforms and experiments are compared to highlight key material properties, advantages, and limitations. The tutorial focuses on a materials-oriented understanding of nonlinear collective-spin sensing, rather than a comprehensive comparison of experimental platforms or a practical guide to sensing experiments.

DOI
10.1088/2633-4356/aeb199

Related papers

Nonlinear collective-spin dynamics for quantum-enhanced sensing in solid-state platforms

Le Bin Ho

Collective spin systems in solid-state materials are promising platforms for quantum-enhanced sensing. In systems such as nitrogen-vacancy centers in diamond, donor spins in silicon, and magnetic materials, interactions among many spins can generate collective quantum correlations that improve measurement precision beyond the standard quantum limit. This tutorial develops an intuitive, materials-oriented framework for understanding these effects through nonlinear collective-spin dynamics. We show how nonlinear interactions reshape collective spin states in phase space, redistribute quantum fluctuations, and generate metrologically useful states such as spin-squeezed and entangled states. We then connect these ideal collective dynamics to microscopic interactions and realistic solid-state systems, discussing how interaction strength, disorder, decoherence, and experimental control affect sensing performance. Different platforms and experiments are compared to highlight key material properties, advantages, and limitations. The tutorial focuses on a materials-oriented understanding of nonlinear collective-spin sensing, rather than a comprehensive comparison of experimental platforms or a practical guide to sensing experiments.

quant-pharXiv:2610.00286•Sep 28, 2026•0 citations

Quantum enhanced metrology with nitrogen-vacancy centers in diamond

Weijie Wu

Solid-state spin defects, particularly the nitrogen-vacancy (NV) center in diamond, have emerged as powerful platforms for exploring quantum many-body physics and quantum metrology. Their exceptional coherence properties and strong dipolar interactions offer unique opportunities to simulate complex quantum dynamics and engineer entangled states for enhanced sensing beyond the standard quantum limit. However, achieving scalable entanglement in these systems is notoriously difficult due to intrinsic disorder and the complex nature of long-range dipole-dipole interactions. This thesis presents both theoretical and experimental advancements in harnessing quantum dynamics in interacting spin ensembles for quantum-enhanced metrology. A central result is the experimental realization of spin squeezing in a dense ensemble of NV centers, demonstrating a clear path toward overcoming classical limits in solid-state platforms. To further formalize and scale these phenomena, this work develops theoretical frameworks for generating robust spin squeezing under realistic experimental conditions. We show that finite-temperature easy-plane magnetism can be actively leveraged to create scalable squeezed states for the dipolar spin systems on regular lattices. Building upon this, we further extend the result to spatially disordered quantum dipoles. We demonstrate that strongly coupled spin pairs suppress squeezing through dynamical heating, and we propose a selective shelving protocol to mitigate this problem. Furthermore, we also propose a universal protocol for quantum-enhanced sensing that exploits information scrambling, utilizing the natural, scrambling dynamics of strongly interacting many-body systems to effectively amplify weak external signals. Together, the findings detailed in this thesis establish a foundational paradigm for controlling and utilizing solid-state spin ensembles, paving the way for entanglement-enhanced quantum sensors.

•Jan 1, 2026•0 citations

Interaction-Enhanced Sensing in Solid-State Spin Ensembles

Haoyang Gao

Solid-state spin ensembles have emerged as a leading platform for micro- and nanoscale sensing, combining high sensitivity, nanoscale spatial resolution, and operation under ambient conditions. At high spin densities, magnetic dipole–dipole interactions typically limit sensing performance by reducing coherence, but can in principle be harnessed to enhance sensitivity. Realizing such interaction-enhanced sensing in practice, however, remains challenging due to the intrinsic anisotropy of dipolar interactions and the random spatial distribution of spins. This thesis presents a series of experimental works that culminate in a practical interaction-enhanced magnetometer based on ensembles of nitrogen-vacancy (NV) centers in diamond. Our approach is based on collective, one-axis-twisting-like (OAT-like) dynamics engineered from native dipolar interactions using controlled nanoscale spin textures, in combination with a dressed-state qubit encoding that significantly extends the sensor coherence time. These results open the door to practical deployment of interaction-enhanced quantum sensors for nanoscale biological imaging and material characterization.

•Jan 1, 2026•0 citations

Quantum Simulation and Nanoscale Sensing of Many-Body Phenomena with Solid-State Spin Defects

G. He

Emergent phenomena in interacting quantum systems arise from collective behavior that cannot be reduced to single-particle physics. Understanding these phenomena requires platforms capable of both synthesizing many-body states under controlled conditions and probing them at the microscopic scale where correlations originate. Solid-state spin defects, including nitrogen-vacancy (NV) centers in diamond and negatively charged boron vacancy centers in hexagonal boron nitride (hBN), offer precisely this dual capability. In the first part of this dissertation, a strongly interacting NV ensemble is subjected to periodic and quasi-periodic drives to access a long-lived prethermal regime and realize a discrete time quasicrystal (DTQC). In the second part, the boron vacancy center in hBN is developed as a two-dimensional quantum sensor through coherence characterization and isotope engineering, then deployed inside a diamond anvil cell to image stress and magnetism simultaneously at gigapascal pressures, resolving a pressure-induced magnetic phase transition in a Cr$_{1+\delta}$Te$_2$/hBN heterostructure. Moreover, NV scanning cross-relaxometry enables nanoscale mapping of spin defects in hBN, while noise spectroscopy is applied to probe superconducting fluctuations and vortex dynamics in a cuprate thin film. Together, these results demonstrate that solid-state spins provide a versatile experimental framework in which quantum simulation, sensor development, and materials characterization inform and reinforce one another.

•Jun 10, 2026•0 citations

Nanoscale magnetometry via collective many-body dynamics in diamond

Haoyang Gao, Piotr Put, Nathaniel T. Leitao +9 more

Many-body dynamics constitutes a promising approach for creating correlations between quantum particles which can be used for applications in sensing and metrology. However, utilizing this potential for substantial gains in practical settings is a challenging task with only a very few applications realized to date. Here, we demonstrate an approach to nanoscale magnetic sensing enabled by strongly interacting electronic spins in a room temperature solid. By coherently controlling collective many-body dynamics of a dipolar ensemble of $\sim 10^4$ nitrogen-vacancy (NV) centres in diamond with pulsed magnetic field gradients, we demonstrate practical metrological gain up to $7.9(2)\,\mathrm{dB}$ for magnetic signal detection and $8.8(3)\,\mathrm{dB}$ for magnetic noise sensing, fully accounting for experimental overheads. Finally, we combine these methods to demonstrate a momentum-space-resolved sensing modality that enables detection of spatially correlated magnetic noise at continuously tunable length scales down to 50 nanometers. These observations open the door toward practical applications of interaction-enhanced quantum sensors for nanoscale biological imaging and material characterization.

quant-pharXiv:2609.03039•Sep 4, 2026•0 citations

Universal Dynamics of Metrologically Useful Entanglement in Strongly Interacting, Disordered Many-Body Systems

Nathaniel Leitao

Controlling the dynamics of targeted quantum correlations is a central goal across many disciplines of quantum science. For applications in nanoscale quantum sensing, nitrogen-vacancy (NV) centers in diamond have recently emerged as a leading platform due to their atom-like nature, exquisite magnetic sensitivity and well-developed coherent control techniques under ambient conditions. However, harnessing the entanglement structure required to improve this sensitivity beyond the standard quantum limit (SQL) from the native dipolar interactions between NV centers is challenging due to their strong positional disorder, three-dimensional geometry and low-fidelity readout. Coupled tightly to proof of principle experimental demonstrations, this thesis provides a theoretical blueprint to realize practical, entanglement-enhanced quantum sensing in the solid-state via far-from-equilibrium dynamics of dense ensembles of NV centers in diamond. Our most fundamental contribution is to identify a universal mechanism exploiting the thermalization of long-wavelength spin textures to generate scalable spin squeezing in the absence of finite temperature symmetry breaking. We further develop a novel sensing protocol based on asymmetric time-reversal capable of rapidly breaking the SQL without high-fidelity readout. Challenging long-standing beliefs in the field, these results open the door to a new era of entanglement-enhanced sensing under ambient conditions, with applications ranging from nanoscale imaging of biological structures to covariance magnetometry of exotic quantum materials.

•Jan 1, 2025•0 citations
Abstract Collective spin systems in solid-state materials are promising platforms for quantum-enhanced sensing. In systems such as nitrogen-vacancy centers in diamond, donor spins in silicon, and magnetic materials, interactions among many spins can generate collective quantum correlations that improve measurement precision beyond the standard quantum limit. This tutorial develops an intuitive, materials-oriented framework for understanding these effects through nonlinear collective-spin dynamics. We show how nonlinear interactions reshape collective spin states in phase space, redistribute quantum fluctuations, and generate metrologically useful states such as spin-squeezed and entangled states. We then connect these ideal collective dynamics to microscopic interactions and realistic solid-state systems, discussing how interaction strength, disorder, decoherence, and experimental control affect sensing performance. Different platforms and experiments are compared to highlight key material properties, advantages, and limitations. The tutorial focuses on a materials-oriented understanding of nonlinear collective-spin sensing, rather than a comprehensive comparison of experimental platforms or a practical guide to sensing experiments.
Collective spin systems in solid-state materials are promising platforms for quantum-enhanced sensing. In systems such as nitrogen-vacancy centers in diamond, donor spins in silicon, and magnetic materials, interactions among many spins can generate collective quantum correlations that improve measurement precision beyond the standard quantum limit. This tutorial develops an intuitive, materials-oriented framework for understanding these effects through nonlinear collective-spin dynamics. We show how nonlinear interactions reshape collective spin states in phase space, redistribute quantum fluctuations, and generate metrologically useful states such as spin-squeezed and entangled states. We then connect these ideal collective dynamics to microscopic interactions and realistic solid-state systems, discussing how interaction strength, disorder, decoherence, and experimental control affect sensing performance. Different platforms and experiments are compared to highlight key material properties, advantages, and limitations. The tutorial focuses on a materials-oriented understanding of nonlinear collective-spin sensing, rather than a comprehensive comparison of experimental platforms or a practical guide to sensing experiments.
Solid-state spin defects, particularly the nitrogen-vacancy (NV) center in diamond, have emerged as powerful platforms for exploring quantum many-body physics and quantum metrology. Their exceptional coherence properties and strong dipolar interactions offer unique opportunities to simulate complex quantum dynamics and engineer entangled states for enhanced sensing beyond the standard quantum limit. However, achieving scalable entanglement in these systems is notoriously difficult due to intrinsic disorder and the complex nature of long-range dipole-dipole interactions. This thesis presents both theoretical and experimental advancements in harnessing quantum dynamics in interacting spin ensembles for quantum-enhanced metrology. A central result is the experimental realization of spin squeezing in a dense ensemble of NV centers, demonstrating a clear path toward overcoming classical limits in solid-state platforms. To further formalize and scale these phenomena, this work develops theoretical frameworks for generating robust spin squeezing under realistic experimental conditions. We show that finite-temperature easy-plane magnetism can be actively leveraged to create scalable squeezed states for the dipolar spin systems on regular lattices. Building upon this, we further extend the result to spatially disordered quantum dipoles. We demonstrate that strongly coupled spin pairs suppress squeezing through dynamical heating, and we propose a selective shelving protocol to mitigate this problem. Furthermore, we also propose a universal protocol for quantum-enhanced sensing that exploits information scrambling, utilizing the natural, scrambling dynamics of strongly interacting many-body systems to effectively amplify weak external signals. Together, the findings detailed in this thesis establish a foundational paradigm for controlling and utilizing solid-state spin ensembles, paving the way for entanglement-enhanced quantum sensors.
Solid-state spin ensembles have emerged as a leading platform for micro- and nanoscale sensing, combining high sensitivity, nanoscale spatial resolution, and operation under ambient conditions. At high spin densities, magnetic dipole–dipole interactions typically limit sensing performance by reducing coherence, but can in principle be harnessed to enhance sensitivity. Realizing such interaction-enhanced sensing in practice, however, remains challenging due to the intrinsic anisotropy of dipolar interactions and the random spatial distribution of spins. This thesis presents a series of experimental works that culminate in a practical interaction-enhanced magnetometer based on ensembles of nitrogen-vacancy (NV) centers in diamond. Our approach is based on collective, one-axis-twisting-like (OAT-like) dynamics engineered from native dipolar interactions using controlled nanoscale spin textures, in combination with a dressed-state qubit encoding that significantly extends the sensor coherence time. These results open the door to practical deployment of interaction-enhanced quantum sensors for nanoscale biological imaging and material characterization.
Emergent phenomena in interacting quantum systems arise from collective behavior that cannot be reduced to single-particle physics. Understanding these phenomena requires platforms capable of both synthesizing many-body states under controlled conditions and probing them at the microscopic scale where correlations originate. Solid-state spin defects, including nitrogen-vacancy (NV) centers in diamond and negatively charged boron vacancy centers in hexagonal boron nitride (hBN), offer precisely this dual capability. In the first part of this dissertation, a strongly interacting NV ensemble is subjected to periodic and quasi-periodic drives to access a long-lived prethermal regime and realize a discrete time quasicrystal (DTQC). In the second part, the boron vacancy center in hBN is developed as a two-dimensional quantum sensor through coherence characterization and isotope engineering, then deployed inside a diamond anvil cell to image stress and magnetism simultaneously at gigapascal pressures, resolving a pressure-induced magnetic phase transition in a Cr1+δ_{1+\delta}1+δ​Te2_22​/hBN heterostructure. Moreover, NV scanning cross-relaxometry enables nanoscale mapping of spin defects in hBN, while noise spectroscopy is applied to probe superconducting fluctuations and vortex dynamics in a cuprate thin film. Together, these results demonstrate that solid-state spins provide a versatile experimental framework in which quantum simulation, sensor development, and materials characterization inform and reinforce one another.
Many-body dynamics constitutes a promising approach for creating correlations between quantum particles which can be used for applications in sensing and metrology. However, utilizing this potential for substantial gains in practical settings is a challenging task with only a very few applications realized to date. Here, we demonstrate an approach to nanoscale magnetic sensing enabled by strongly interacting electronic spins in a room temperature solid. By coherently controlling collective many-body dynamics of a dipolar ensemble of ∼104\sim 10^4∼104 nitrogen-vacancy (NV) centres in diamond with pulsed magnetic field gradients, we demonstrate practical metrological gain up to 7.9(2) dB7.9(2)\,\mathrm{dB}7.9(2)dB for magnetic signal detection and 8.8(3) dB8.8(3)\,\mathrm{dB}8.8(3)dB for magnetic noise sensing, fully accounting for experimental overheads. Finally, we combine these methods to demonstrate a momentum-space-resolved sensing modality that enables detection of spatially correlated magnetic noise at continuously tunable length scales down to 50 nanometers. These observations open the door toward practical applications of interaction-enhanced quantum sensors for nanoscale biological imaging and material characterization.
Controlling the dynamics of targeted quantum correlations is a central goal across many disciplines of quantum science. For applications in nanoscale quantum sensing, nitrogen-vacancy (NV) centers in diamond have recently emerged as a leading platform due to their atom-like nature, exquisite magnetic sensitivity and well-developed coherent control techniques under ambient conditions. However, harnessing the entanglement structure required to improve this sensitivity beyond the standard quantum limit (SQL) from the native dipolar interactions between NV centers is challenging due to their strong positional disorder, three-dimensional geometry and low-fidelity readout. Coupled tightly to proof of principle experimental demonstrations, this thesis provides a theoretical blueprint to realize practical, entanglement-enhanced quantum sensing in the solid-state via far-from-equilibrium dynamics of dense ensembles of NV centers in diamond. Our most fundamental contribution is to identify a universal mechanism exploiting the thermalization of long-wavelength spin textures to generate scalable spin squeezing in the absence of finite temperature symmetry breaking. We further develop a novel sensing protocol based on asymmetric time-reversal capable of rapidly breaking the SQL without high-fidelity readout. Challenging long-standing beliefs in the field, these results open the door to a new era of entanglement-enhanced sensing under ambient conditions, with applications ranging from nanoscale imaging of biological structures to covariance magnetometry of exotic quantum materials.