Work

Direct Observation of Dipolar-Driven Anisotropic Quantum Projection Noise in a Solid-State Spin Ensemble

Year: 2026

Type: preprint

Abstract: The nitrogen-vacancy (NV) center in diamond is a prominent quantum-sensing platform. Combining readout at the quantum projection noise limit with strong dipolar interactions promises substantial gains in sensitivity. However, experimentally accessing this regime has remained a longstanding challenge. In this work, we demonstrate quantum-projection-noise-resolved readout of a strongly-interacting, two-dimensional ensemble of NV centers. Our approach leverages repetitive readout via the NV's intrinsic $^{15}$N nuclear memory at a moderate magnetic field ($\sim 0.3$ T), improving the readout fidelities by nearly an order of magnitude. This enables us to directly resolve the quantum projection noise of a coherent spin state and to watch the ensemble's intrinsic dipolar interactions shear this noise into an anisotropic profile. Our results open the door to direct measurements of spin squeezing and entanglement-enhanced sensing in the solid state.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2609.16106

Authors: Ono, Tasuku, Wu, Weijie, Yang, Haopu, Wyatt, Lillian B. Hughes, Brenner, Benjamin, Liu, Che, Fan, Collin, Laumann, Chris R., Hallén, Jonathan N., Davis, Emily J., Jayich, Ania C. Bleszynski, Yao, Norman Y.

Institutions: MIT-Harvard Center for Ultracold Atoms, Massachusetts Institute of Technology, Harvard University, Boston University, New York University, University of California, Santa Barbara

Language: English

Topic: Diamond and Carbon-based Materials Research

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, U.S. Department of Energy, Sweden-America Foundation, University of California, Santa Barbara, Materials Research Science and Engineering Center, Harvard University, Multidisciplinary University Research Initiative, Division of Materials Research, California NanoSystems Institute, Army Research Office

Awards: G1797871914, G2045646697, G2450830071, G3236695045, G325663671, G4250104368, G493656753, G501274426, G5884252700, G5975534213, G6512159266, G6692005437, Materials Research Science and Engineering Center at UCSB, G7437795455, G7452299184, Enabling Quantum Leap: Q-AMASE-i: Quantum Foundry at UCSB

OpenAlex ID: W7213422766

Cites: 2

Cited by:

Related to: 10