Xin Mingjie, Leong Wui Seng, Chen Zilong, Wang Yu, Lan Shau-Yu
Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
Phys Rev Lett. 2021 Oct 29;127(18):183602. doi: 10.1103/PhysRevLett.127.183602.
Quantum sensing and quantum information processing use quantum advantages such as squeezed states that encode a quantity of interest with higher precision and generate quantum correlations to outperform classical methods. In harmonic oscillators, the rate of generating squeezing is set by a quantum speed limit. Therefore, the degree to which a quantum advantage can be used in practice is limited by the time needed to create the state relative to the rate of unavoidable decoherence. Alternatively, a sudden change of harmonic oscillator's frequency projects a ground state into a squeezed state which can circumvent the time constraint. Here, we create squeezed states of atomic motion by sudden changes of the harmonic oscillation frequency of atoms in an optical lattice. Building on this protocol, we demonstrate rapid quantum amplification of a displacement operator that could be used for detecting motion. Our results can speed up quantum gates and enable quantum sensing and quantum information processing in noisy environments.
量子传感和量子信息处理利用量子优势，如压缩态，它能以更高精度对感兴趣的量进行编码，并产生量子关联以超越经典方法。在简谐振子中，产生压缩的速率由量子速度极限设定。因此，量子优势在实际中能够被利用的程度受到相对于不可避免的退相干速率创建态所需时间的限制。或者，简谐振子频率的突然变化会将基态投影到压缩态，这可以规避时间限制。在此，我们通过光学晶格中原子简谐振荡频率的突然变化来创建原子运动的压缩态。基于此协议，我们展示了位移算符的快速量子放大，其可用于检测运动。我们的结果能够加速量子门，并在有噪声的环境中实现量子传感和量子信息处理。
