Optical Probe of Quantum Shot Noise Reduction at a Single-Atom Contact

Signature of Coherent Transport in Epitaxial Spinel-based Magnetic Tunnel Junctions Probed by Shot Noise Measurement

We measured the shot noise in fully epitaxial Fe/MgAl2OX/Fe-based magnetic tunneling junctions (MTJs). While the Fano factor to characterize the shot noise is very close to unity in the antiparallel configuration, it is reduced to 0.98 in the parallel configuration. This observation shows the sub-Poissonian process of electron tunneling in the parallel configuration, indicating the coherent tunneling through the spinel-based tunneling barrier of the MTJ.

Scanning probe-induced thermoelectrics in a quantum point contact

We study three-terminal thermoelectric transport in a two-dimensional Quantum Point Contact (QPC) connected to left and right electronic reservoirs, as well as a third one represented by a scanning probe tip. The latter acts as a voltage probe exchanging heat with the system but no charges on average. The thermoelectric coefficients are calculated numerically within the Landauer-Büttiker formalism in the low-temperature and linear response regimes. We find tip-induced oscillations of the local and non-local thermopowers and study their dependence on the QPC opening. If the latter is tuned on a…

Klein tunneling through the trapezoidal potential barrier in graphene: conductance and shot noise

When a single-layer graphene sheet is contacted with metallic electrodes, tunnel barriers are formed as a result of the doping of graphene by the metal in the contact region. If the Fermi energy level is modulated by a gate voltage, the phenomenon of Klein tunneling results in specific features in the conductance and noise. Here we obtain analytically exact solutions for the transmission and reflection probability amplitudes using a trapezoidal potential barrier, allowing us to calculate the differential conductance and the Fano factor for a graphene sheet in the ballistic regime. We put in ev…

最大纠缠探针在单次酉矩阵可区分性中的局限性

Limitation of maximally entangled probes for single-shot distinguishability of unitaries

研究单次区分两个酉通道时纠缠态与积态的等效性，找出用非最大纠缠态可区分但最大纠缠态不能区分的酉矩阵对，还表明在特定维度存在用最大纠缠探针不可区分但其他态可区分的酉矩阵类。

单次鉴别噪声量子通道

Single shot distinguishability of noisy quantum channels

研究单次鉴别噪声量子通道，分析单系统与纠缠探针在不同噪声下的最优性能及作用

单次反区分性单位元操作

Single-shot antidistinguishability of unitary operations

本文研究了单次单位元操作的反区分性，证明了在某些情况下最大化纠缠探测器的必要性，并展示了如何从非反区分单位元构造反区分单位元。