Observation of off-diagonal geometric phase in polarized neutron interferometer experiments

Theoretical analysis of a Polarized Two-Photon Michelson Interferometer with Broadband Chaotic Light

In this paper, we study two-photon interference of broadband chaotic light in a Michelson interferometer with two-photon-absorption detector. The theoretical analysis is based on two-photon interference and Feynman path integral theory. The two-photon coherence matrix is introduced to calculate the second-order interference pattern with polarizations being taken into account. Our study shows that the polarization is another dimension, as well as time and space, to tune the interference pattern in the two-photon interference process. It can act as a switch to manipulate the interference process…

Improvement of the polarized neutron interferometer setup demonstrating violation of a Bell-like inequality

For precise measurements with polarized neutrons high efficient spin-manipulation is required. We developed several neutron optical elements suitable for a new sophisticated setup, i.e., DC spin-turners and Larmor-accelerators which diminish thermal disturbances and depolarisation considerably. The gain in performance is exploited demonstrating violation of a Bell-like inequality for a spin-path entangled single-neutron state. The obtained value of S=2.365(13), which is much higher than previous measurements by neutron interferometry, is 28 $σ$ above the limit of S=2 predicted by contextual hi…

严格非相干操作框架下的相干度量及其在多路径干涉仪中的应用

Coherence measures in the strictly incoherent operation framework and its application in the multi-path interferometer

本文在严格非相干操作框架下，基于保真度提出一种新的相干度量，推导其解析表达式及与其他度量的关系，证明其单调性，并将其应用于多路径干涉仪中波动性的刻画，给出保真度形式的波粒二象性关系。

Real-time dynamics of spin-dependent transport through a double-quantum-dot Aharonov-Bohm interferometer with spin-orbit interaction

The spin-resolved non-equilibrium real-time electron transport through a double-quantum-dot (DQD) Aharonov-Bohm (AB) interferometer with spin-orbit interaction (SOI) is explored. The SOI and AB interference in the real-time dynamics of spin transport is expressed by effective magnetic fluxes. Analytical formulae for the time-dependent currents, for initially unpolarized spins, are presented. In many cases, there appear spin currents in the electrodes, for which the spins in each electrode are polarized along characteristic directions, pre-determined by the SOI parameters and by the geometry of…

New Aspects of Geometric Phases in Experiments with polarized Neutrons

Geometric phase phenomena in single neutrons have been observed in polarimeter and interferometer experiments. Interacting with static and time dependent magnetic fields, the state vectors acquire a geometric phase tied to the evolution within spin subspace. In a polarimeter experiment the non-additivity of quantum phases for mixed spin input states is observed. In a Si perfect-crystal interferometer experiment appearance of geometric phases, induced by interaction with an oscillating magnetic field, is verified. The total system is characterized by an entangled state, consisting of neutron an…

Telecom-band Multi-Type Spontaneous Parametric Downconversion in Periodically Polarized Nonlinear Materials

Spontaneous parametric downconversion is an essential technique in quantum optics experiments. In this paper, various quasi-phase-matching processes in several typical periodically polarized nonlinear materials are analyzed and calculated. Furthermore, a general method for realizing multiple types of quasi-phase-matching in a monolithic material is presented. Finally, a novel design to prepare multiple entangled photon pairs based on the Sagnac interferometer is discussed. This technology can be applied to tiny optical paths in the telecom C band, saving both cost and space.