Effects of spin-exchange collisions in a high-density alkali-metal vapor in low magnetic fields
Effects of spin-exchange collisions in a high-density alkali-metal vapor in low magnetic fields
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DOI：
10.1103/physreva.71.023405
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发表时间：
2005-02-01
影响因子：
2.9
通讯作者：
Romalis, MV
中科院分区：
文献类型：
--
作者：
Savukov, IM;Romalis, MV
自旋交换碰撞通常在碱金属蒸气中塞曼共振的展宽中起主导作用。与直觉预期相反，在高碱金属密度下，可以通过在低磁场中操作来完全消除这种展宽，从而允许构造超灵敏原子磁力计。我们描述了对塞曼共振频率和线宽作为磁场、碱金属密度和原子自旋极化程度的函数的详细研究。由于描述自旋交换碰撞的密度矩阵方程的非线性性质，旋磁比和线宽都作为偏振的函数而变化。实验测量结果与密度矩阵方程的解析解和数值解非常一致。
Spin-exchange collisions often play a dominant role in the broadening of Zeeman resonances in an alkali-metal vapor. Contrary to intuitive expectations, at high alkali-metal densities this broadening can be completely eliminated by operating in a low magnetic field, allowing construction of ultrasensitive atomic magnetometers. We describe a detailed study of the Zeeman resonance frequencies and linewidths as a function of the magnetic field, alkali-metal density, and the degree of spin polarization of the atoms. Due to the nonlinear nature of the density matrix equations describing the spin-exchange collisions both the gyromagnetic ratio and the linewidth change as a function of the polarization. The results of experimental measurements are in excellent agreement with analytical and numerical solutions of the density matrix equations.