We report successful manipulation of non-classical atomic spin states. We generate squeezed spin states by a spin quantum nondemolition measurement, and apply an off-resonant circularly-polarized light pulse to the atoms. By changing the pulse duration, we have clearly observed a rotation of anisotropic quantum noise distribution in good contrast with the case of manipulation of a coherent spin state where the quantum noise distribution is always isotropic. This is an important step for quantum state tomography, quantum swapping, and precision spectroscopic measurement.
@article{arxiv.0909.2423,
title = {Manipulation of Non-classical Atomic Spin States},
author = {Tetsushi Takano and Shin-Ichi-Ro Tanaka and Ryo Namiki and Yoshiro Takahashi},
journal= {arXiv preprint arXiv:0909.2423},
year = {2015}
}