Quantum Magnetoresistive (hc/2e)/m-Periodic Oscillations in a Superconducting Ring

JETP Letters - It has been found experimentally that quantum magnetoresistive hc/2e-periodic Little-Parks oscillations in a mesoscopic superconducting ring with a decrease in the temperature and an...     

Raman Scattering by Plasma Oscillations in Quantum Rings

Resonant Raman scattering in quantum rings with a sufficiently large number of conduction electrons has been studied. The cross section for Raman scattering accompanied by the excitation of a one-dimensional plasmon in a ring has been determined in the self-consistent field approximation.     

Quantum Effect in Mesoscopic Open Electron Resonator

The open electron resonator is a mesoscopic device that has attracted considerable attention due to its remarkable behavior： conductance oscillations. In this paper, using an improved quantum theory to mesoscopic circuits developed recently by Li and Chen, the mesoscopic electron resonator is quantized based on the fundamental fact that the electric charge takes discrete value. With presentation transformation and unitary transformation, the SchrSdinger equation becomes an standard Mathieu equation. Then, the detailed energy spectrum and wave functions in the system axe obtained, which will be helpful to the observation of other characters of electron resonator. The average of currents and square of the current are calculated, the results show the existence of the current fluctuation, which causes the noise in the circuits, the influence of inductance to the noise is discussed. With the results achieved, the stability characters of mesoscopic electron resonator are studied firstly, these works would be benefit to the design and control of integrate circuit.     

Measure h/e2 by counting electrons or ions in a storage ring

Storage rings offer the possibility of realizing a current by counting the electrons or ions per second passing through a toroidal SQUID current comparator. This technique offers the possibility of accurately measuring the quantity h/e² and providing a stringent test of the quantum Hall effect.     

用Josephson结电子模拟器测量磁通量子2e/h

介绍用Josephson结电子模拟器在政党温度下，模拟测量磁通量子2e/h，用模拟器来研究Josephosn结的特性。该实验可作为普通物理实验中课题设计实验的一个内容。     

冷原子系综中量子关联光子对的产生

本文在87 Rb冷原子系综中通过自发拉曼散射过程进行了量子关联光子对产生的实验研究,测量了关联光子对的产生率和二阶关联函数g(2)随写光激发率、读光功率以及写光失谐等实验参数的关系曲线。结果表明:随着写光激发率的增加,光子对产生率线性增加,g(2)则不断减小;在小的读光功率处,光子对产生率和g(2)随着读光功率增加而增大,当读光功率超过30 mW后,产生率和g(2)随着读光功率增加反而有所下降;写光频率失谐为-5 MHz时光子对产生率和g(2)均达到最低,增大或减小写光失谐产生率和g(2)均逐渐增加。通过选取合适的实验参数,光子对产生率达到18对/秒,同时g(2)为106。本文的研究结果为产生高质量的纠缠源提供了实验基础。     

Electron dichroism effects in the relativistic (e, 2e) process for K-shell ionization of atoms

In this communication we present theoretical demonstration of electron dichroism in the relativistic (e, 2e) process for K-shell ionization of atoms in non-coplanar asymmetric geometry. The theoretical formalism has been developed in plane wave Born approximation and in this approximation the triple differential cross-section (TDCS) has been expressed as a product of kinematical factors and atomic structure functions. The longitudinal spin asymmetry in the relativistic (e, 2e) process on K-shell of atoms has been shown to depend on the interference between the transition charge and component of the transition current in the direction perpendicular to the scattering plane. Further, the longitudinal spin asymmetry has been shown to depend on incident electron energy, atomic number of the target, azimuthal angle of the ejected electron and scattered electron angle.     

Interaction strength and shape difference for the h9/2 and h11/2 configurations in163Tm

The strongly shape driving πh_9/2[541]l/2^? configuration with α=+1/2 exhibits some anomalous, and so far unexplained, features concerning the crossing frequency, ?ω_c, the aligned angular momentum, i_x, and interaction strength, at the alignment of the first pair of i_13/2 quasineutrons in several odd-Z rare earth-nuclei. The h_9/2[541]1/2^? and h_11/2[523]7/2^? bands have been studied in the stably deformed rare-earth nucleus¹⁶³Tm to investigate these features. A difference in band crossing frequency of ～ 80 keV between the two bands is found. Rotational bands built on these two configurations have been found to cross in the spin range I=25/2–29/2 ?. Theγ-decay pattern between the two bands is established in the crossing region and analysed in terms of a moderate shape difference between them. A theoretical estimate of the size of the interaction strength between the two bands is presented and compared to the experimental value. The observed band structure in¹⁶³Tm is very similar to that of¹⁶⁷Lu which has 2 protons and 2 neutrons in addition. This observation is discussed in relation to the similarity of the yrast bands of the two even-even “core” nuclei¹⁶²Er and¹⁶⁶Yb, for which theγ-transition energies are identical within ～0.2 keV below the vi_13/2 crossing.     

Non-Classical Correlated Photon Pairs Generation via Cascade Transition of 5S1/2-5P3/2-5D5/2 in a Hot SSRb Atomic Vapor

We experimentally prepare the non-classical correlated photon pairs at the wavelengths of 780 and 776 mn via the cascade transition of 5S1/2 5P3/2-5D5/2 in a hot SSRb atomic ensemble. By measuring the function of cross-correlation and auto-correlation of photons, a violation of Cauehy Schwarz inequality by a factor of 283 is obtained, which clearly indicates a strong non-classicM correlation between the generated photons. We also find that noise photons scattered from pump lasers have a strong effect on the Cauchy-Schwarz inequality factor by changing the intensity of the pump laser, the experimental results are consistent with the theoretical predictions.     

冷原子系综中偏振关联光子对的产生和测量

我们在~(87)Rb冷原子系综中进行了关联光子对的产生和测量。通过自发拉曼散射过程,产生了一个Stokes光子和一个原子自旋波激发。利用电磁感应透明效应将存储在原子系综中的自旋波转化为一个anti-Stokes光子。在两相互正交的偏振基下,测量了Stokes光子和anti-Stokes光子之间的交叉关联函数。实验结果表明,交叉关联函数g~(2)达到~75,表现了强的非经典关联。基于现场可编程门阵列(FPGA)的自编程的多通道符合器被用于光子脉冲信号的采集和逻辑处理,大大提高了偏振关联光子对的产生和测量速度,为以后量子中继技术中的高效信息处理提供了重要基础。     

利用高非线性光纤产生量子关联光子对的实验研究

光纤中基于三阶(克尔)非线性效应的自发四波混频是制备量子关联光子对的有效方法之一。若采用商售高非线性光纤作为产生光子对的非线性介质,则有利于减小所需光纤的长度,从而缩小实验装置体积并降低对于抽运源的要求。利用脉冲光抽运20m的高非线性光纤产生通讯波段的频率近简并关联光子对,研究了光纤的弱双折射特性对于光子对产生的影响。当抽运光沿高非线性光纤的偏振轴入射时,具有最大的光子对产生效率,且光子对绝大部分与抽运光偏振平行;抽运光沿与光纤偏振轴45°入射时,光子对的产生效率最小,约为最大值的80%。     

Dimension Effects in Insulating NbTiN Disordered Films and the Asymptotic Freedom of Cooper Pairs

JETP Letters - We investigate the evolution of the electronic transport in disordered NbTiN films at the insulating side of the superconductor-insulator transition as function of the effective...