发展固态量子信息与计算的实验研究

量子计算与量子信息是21世纪基础和应用科学研究的一大挑战.要实现实用意义上的量子信息和量子计算,必须解决量子比特系统的可拓展性问题.基于现代半导体技术的固态量子系统,其应用和最终产业化的可行性较高.然而,固态量子体系受周边环境的影响比较严重,控制其退相干,维持其量子状态的难度更高.实验固态量子计算的研究是个新的领域,尚无实用的技术和方法. 文章介绍了中国科学院物理研究所固态量子信息和计算实验室近几年来新开辟的自旋、冷原子、量子点(包括原子空位)、功能氧化物和关联体系等固态量子信息的新载体和同量子计算与量子信息相关的科学与技术难题的实验研究.     

发展固态量子信息与计算的实验研究

量子计算与量子信息是21世纪基础和应用科学研究的一大挑战. 要实现实用意义上的量子信息和量子计算,必须解决量子比特系统的可拓展性问题.基于现代半导体技术的固态量子系统,其应用和最终产业化的可行性较高. 然而,固态量子体系受周边环境的影响比较严重,控制其退相干,维持其量子状态的难度更高.实验固态量子计算的研究是个新的领域,尚无实用的技术和方法. 文章介绍了中国科学院物理研究所固态量子信息和计算实验室近几年来新开辟的自旋、 冷原子、 量子点(包括原子空位)、功能氧化物和关联体系等固态量子信息的新载体和同量子计算与量子信息相关的科学与技术难题的实验研究.     

Enhanced Loading of ~(40)K from Natural Abundance Potassium Source with a High Performance 2D~+ MOT

~(40)K is one of the most important atomic species for ultra-cold atomic physics. Due to the extremely low concentration(0.012%) of ~(40)K in natural abundance of potassium, most experiments use 4–10% enriched potassium source, which have greatly suffered from the extremely low annual production and significant price hikes in recent years. Using naturally abundant potassium source, we capture 5.4 × 10~6 cold ~(40)K atoms with the help of a high performance of two-dimensional magneto-optical trap(2D~+MOT), which is almost three orders of magnitude greater than previous results without the 2D~+ MOT. The number of the ~(40)K atoms is sufficient for most ultra-cold ~(40)K experiments, and our approach provides an ideal alternative for the field.     

Autler–Townes spectroscopy of high-lying state by phase conjugate six-wave mixing

An Autler-Townes(AT) spectroscopy based on phase conjugate six-wave mixing(SWM) is proposed to detect AT doublet of high-lying state in a Doppler-broadened cascade four-level system.It is found that the SWM spectrum is dependent strongly on the ratios between the magnitudes of the wave vectors.We discuss how the Doppler broadening affects the SWM spectrum from a time-domain viewpoint and find that,due the atomic motion,the atomic polarizations acquire different phases for atoms with different velocities as time evolves.The Doppler free SWM spectrum can be obtained only when the atomic polarization can be rephasing again at certain time after the interactions of all the incident fields.     

出人意料的电子电偶极矩上限

<正>几十年来,实验物理学家都在尝试利用原子或分子束技术来测量电子的电偶极矩(EDM)。尽管还没有测出电子电偶极矩的具体大小,他们却不断地给出了更精确的电子电偶极矩上限值。这些实验通常在普通实验室的光学平台上进行,却对粒子物理研究有重要价值,而粒子物理实验通常是在巨大的粒子加速器上进行的。不少物理学家认为,EDM实验是用于研究超出粒子物理标准模型的新物理的最快和最廉价的手段。电子在自然定律违反时间反演     

Rb87冷原子电磁感应透明吸收曲线不对称性的分析

研究了耦合光共振时Rb⁸⁷冷原子D1线Λ形能级体系中电磁感应透明吸收曲线的不对称现象.发现间隔为814 MHz的另一个激发态能级导致了不对称现象.不对称现象的根本原因是受激拉曼散射, 同时发现透明窗口两侧不对称的吸收峰的幅值比与耦合光强成正比.理论拟合与实验数据符合得较好.     

Ultra-High Efficiency Magnetic Transport of SZRb Atoms in a Single Chamber Bose-Einstein Condensation Apparatus

We report the ultra-high efficiency transport of cold ST Ftb atoms using a moving magnetic quadrupole potential generated by three overlapping pairs of fixed coils. The transfer etticiency is better than 97%, which is the highest ever reported to our knowledge. The temperature increase due to heating is less than IO #K when the initial cloud temperature is llO#K. Our setup is similar to the magnetic transferring belt design [Phys. ftev. A 63 （2001）031401（R）], although it is simpler because the push coil is not required. We use it to transport atoms away from a magneto-optical trap to very close to the wall of the glass cell, facilitating future experiments employing three-dimensional optical lattices, high resolution in-situ imaging, and magnetic Feshbach resonances.     

Spin dynamics of the potassium magnetometer in spin-exchange relaxation free regime

The laser-pumped potassium spin-exchange relaxation free(SERF) magnetometer is the most sensitive detector of magnetic field and has many important applications. We present the experimental results of our potassium SERF magnetometer. A pump–probe approach is used to identify the unique spin dynamics of the atomic ensemble in the SERF regime.A single channel sensitivity of 8 f·THz-1/2is achieved with our SERF magnetometer.     

出人意料的电子电偶极矩上限

几十年来,实验物理学家都在尝试利用原子或分子束技术来测量电子的电偶极矩(EDM)。尽管还没有测出电子电偶极矩的具体大小,他们却不断地给出了更精确的电子电偶极矩上限值。这些实验通常在普通实验室的光学平台上进行,却对粒子物理研究有重要价值,而粒子物理实验通常是在巨大的粒子加速器上进行的。不少物理学家认为,EDM实验是用于研究超出粒子物理标准模型的新物理的最快和最廉价的手段。     

Quantum synchronization with correlated baths

We study quantum synchronization under the nonequilibrium reservoirs. We consider a two-qubit X X Z chain coupled independently to their own reservoirs modeled by the collisional model. Two reservoir particles, initially prepared in a thermal state or a state with coherence, are correlated through a unitary transformation and afterward interact locally with the two quantum subsystems. We study the quantum effect of reservoir on synchronous dynamics of system. By preparing different reservoir ini...