We study two aspects of measurement theory in spinor Bose-Einstein condensates of $F=1$ atoms: the probability of obtaining a certain outcome of the measurement and the evolution of the state of the condensate due to the measurement. We also study the interference patterns arising from the spatial overlap of two spinor condensates. We show that neither a measurement on a small number of escaping atoms nor an interference experiment can distinguish between an antiferromagnetic coherent state condensate, i.e., a condensate in which all the atoms have ${S}_{z}=0$ along an a priori unknown direction, and a spin-singlet condensate, i.e., a condensate with ${S}_{\mathrm{total}}=0.$ We also show that a singlet-state condensate evolves into a coherent state as a result of the measurement.We study two aspects of measurement theory in spinor Bose-Einstein condensates of $F=1$ atoms: the probability of obtaining a certain outcome of the measurement and the evolution of the state of the condensate due to the measurement. We also study the interference patterns arising from the spatial overlap of two spinor condensates. We show that neither a measurement on a small number of escaping atoms nor an interference experiment can distinguish between an antiferromagnetic coherent state condensate, i.e., a condensate in which all the atoms have ${S}_{z}=0$ along an a priori unknown direction, and a spin-singlet condensate, i.e., a condensate with ${S}_{\mathrm{total}}=0.$ We also show that a singlet-state condensate evolves into a coherent state as a result of the measurement.

Physical Review AJan 17, 200221 citations

Creating, imaging, and analyzing magnetic structures in a spinor BEC

Sean Lourette, G. Edward Marti, Ryan Olf +1 more

Bulletin of the American Physical SocietyJun 4, 20130 citations

Measurement of a spin-1 system

Antonio Di Lorenzo

arXiv:1309.2127Physics Letters AFeb 27, 20153 citations

Implementation of a double-path multi-mode interferometer using spinor BEC

Pengju Tang, Xiangyu Dong, Wenjun Zhang +3 more

We realize a double-path multimode matter wave interferometer with spinor Bose-Einstein condensate and observe clear spatial interference fringes as well as a periodic change of the visibility in the time domain, which we refer to as the time domain interference and which is different from the traditional double-path interferometer. By changing the relative phase of the two paths, we find that the spatial fringes first lose coherence and recover. As the number of modes increases, the time domain interference signal with the narrower peaks is observed, which is beneficial to the improvement of the resolution of the phase measurement. We also investigated the influence of initial phase configuration and phase evolution rate between different modes in the two paths. With enhanced resolution, the sensitivity of interferometric measurements of physical observables can also be improved by properly assigning measurable quantities to the relative phase between two paths.We realize a double-path multimode matter wave interferometer with spinor Bose-Einstein condensate and observe clear spatial interference fringes as well as a periodic change of the visibility in the time domain, which we refer to as the time domain interference and which is different from the traditional double-path interferometer. By changing the relative phase of the two paths, we find that the spatial fringes first lose coherence and recover. As the number of modes increases, the time domain interference signal with the narrower peaks is observed, which is beneficial to the improvement of the resolution of the phase measurement. We also investigated the influence of initial phase configuration and phase evolution rate between different modes in the two paths. With enhanced resolution, the sensitivity of interferometric measurements of physical observables can also be improved by properly assigning measurable quantities to the relative phase between two paths.

Oct 24, 20190 citations

Experimental Realization of a Mach–Zehnder-Type Internal-State Atom Interferometer in Sodium Spinor BEC

Jun Jian, 赵竹芳, Quanxin Zhang +5 more

This study demonstrates a Mach–Zehnder-type internal-state atom interferometer in a sodium F = 1 spinor Bose–Einstein condensate (BEC), which is realized by applying a three-pulse radio-frequency sequence (π/2–π–π/2) to manipulate the two magnetic sublevels |1,−1⟩ and |1,0⟩. Phase-scanning experiments show that the visibility remains at a high level across all three pulse stages (V>0.77). In the hold-time scanning measurements, the visibility decays exponentially with hold time, yet the system maintains good coherence. This work establishes a foundation for precision measurements based on internal-state atom interferometers, as the approach simplifies the experimental apparatus while maintaining good quantum coherence and high-contrast interference fringes.This study demonstrates a Mach–Zehnder-type internal-state atom interferometer in a sodium F = 1 spinor Bose–Einstein condensate (BEC), which is realized by applying a three-pulse radio-frequency sequence (π/2–π–π/2) to manipulate the two magnetic sublevels |1,−1⟩ and |1,0⟩. Phase-scanning experiments show that the visibility remains at a high level across all three pulse stages (V>0.77). In the hold-time scanning measurements, the visibility decays exponentially with hold time, yet the system maintains good coherence. This work establishes a foundation for precision measurements based on internal-state atom interferometers, as the approach simplifies the experimental apparatus while maintaining good quantum coherence and high-contrast interference fringes.

PhotonicsJan 30, 20260 citations

BEC magnetometry as a probe of hybrid quantum systems

Collin Reynolds, Chandler Kemp, Eli J. Fox +2 more

Bulletin of the American Physical SocietyJun 5, 20120 citations

We study two aspects of measurement theory in spinor Bose-Einstein condensates of

F=1

atoms: the probability of obtaining a certain outcome of the measurement and the evolution of the state of the condensate due to the measurement. We also study the interference patterns arising from the spatial overlap of two spinor condensates. We show that neither a measurement on a small number of escaping atoms nor an interference experiment can distinguish between an antiferromagnetic coherent state condensate, i.e., a condensate in which all the atoms have

{S}_{z}=0

along an a priori unknown direction, and a spin-singlet condensate, i.e., a condensate with

{S}_{\mathrm{total}}=0.

We also show that a singlet-state condensate evolves into a coherent state as a result of the measurement.