Anomalous noise spectra in a spin-exchange-relaxation-free alkali-metal vapor

Abstract

We perform spin-noise spectroscopy on an unpolarized ${}^{87}\mathrm{Rb}$ vapor in the spin-exchange-relaxation-free (SERF) regime. We observe noise spectral distributions that deviate strongly from Lorentzian models that accurately describe lower-density regimes. For example, at magnetic fields of $\sim 1\mu \mathrm{T}$ and ${}^{87}\mathrm{Rb}$ densities $\gtrsim 1\times 10^{14}atoms/c{\mathrm{m}}^3$ we observe an asymmetric spin-noise distribution in which the resonance line is depleted by about half its power, with the diverted power becoming a broad spectral component that could be mistaken for optical shot noise. The results are in good agreement with recent models accounting for correlations between the ground hyperfine states. We discuss implications for quantum sensing and absolute noise calibration in spin-squeezing and entanglement detection.

References in corpus (24)

• Nuclear spin gyroscope based on an atomic co-magnetometer
• States of an Ensemble of Two-Level Atoms with Reduced Quantum Uncertainty
• Squeezed-Light Optical Magnetometry
• Spectroscopy of spontaneous spin noise as a probe of spin dynamics and magnetic resonance
• Spin noise spectroscopy in GaAs
• Spin squeezing of atomic ensembles via nuclear-electronic spin entanglement
• Improved Limits on Spin-Mass Interactions
• High Bandwidth Atomic Magnetometery with Continuous Quantum Non-demolition Measurements
• Generation of a squeezed state of an oscillator by stroboscopic back-action-evading measurement
• Semiconductor Spin Noise Spectroscopy: Fundamentals, Accomplishments, and Challenges
• The Theory of Spin Noise Spectroscopy: A Review
• Measurement-induced nonlocal entanglement in a hot, strongly-interacting atomic system
• Squeezed-light spin noise spectroscopy
• Signal tracking beyond the time resolution of an atomic sensor by Kalman filtering
• Quantum interface for noble-gas spins based on spin-exchange collisions
• Quantum Dynamics of Collective Spin States in a Thermal Gas
• Correlation function of spin noise due to atomic diffusion
• Effects of spin-exchange collisions on the fluctuation spectra of hot alkali-metal vapors
• Quantum nonlinear spectroscopy of single nuclear spins
• Sensitivity, quantum limits, and quantum enhancement of noise spectroscopies
• Spin and Valley Noise in Two-Dimensional Dirac Materials
• Spin-exchange collisions in hot vapors create and sustain bipartite entanglement
• Collision-induced spin noise
• Zero-field spin noise spectrum of an alkali vapor with strong spin-exchange coupling

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