Quantum Interference Effects in Quantum Dot Molecular With Majorana Bound States

Non-invasive detection of the Majorana bound state (MBSs), a kind of quasiparticle without charge and mass, is one of the core issues in current condensed matter physics. Here we study in theory the quantum interference effect in parallel-coupled double quantum dots which are connected either by Majorana bound states (MBSs) or regular fermions. We find that the zero-energy conductance develops a sharp peak when the dots are connected by the MBSs, whereas that in the case of the dots are coupled via regular fermions shows a valley. By varying the coupling strength between the dots and the electron reservoirs, the conductance in the two structures changes in different ways. By comparing the properties of the linear conductance in the two systems, the information of the MBSs formed at the two ends of a topological superconductor nanowire then can be inferred. We also find that the MBSs in the present structure also induces the Fano effect, and is favorable in quantum information processing.

Modulation of destructive quantum interference by bridge groups in truxene-based single-molecule junctions

Nitrogen and carbonyl bridge substituents embedded in truxene derivatives enhance the single-molecule conductance prominently by alleviating the destructive quantum interference effect and pushing away the anti-resonance dip from the Fermi energy.

Variable Optical Buffer Using EIT in Three Level System Based on Semiconductor Conical Quantum Dots

A variable semiconductor optical buffer based on the electromagnetically induced transparency (EIT) in a three level conical quantum dot system (CQD) is theoretically investigated. The system is interacting with two (control and signal) laser beams. Signal light with subluminal velocity is possible in such system through the quantum interference effect induced by the control pump field. We investigate the refractive index and absorption spectra of the QD waveguide at different pump levels, which exhibit an optimal pump power for maximum slow-down factor (SDF). The group velocity SDF is theoretically analyzed as a function of the pump intensity at different broadened linewidths. The present study is based on the assumption that the medium is homogeneous. In this paper, a SDF as a function of CQD radius was studied. The simulation results indicate that the SDF increases with decreasing CQD radius.

High Positive MR and Energy Band Structure of RuSb2+

A high positive magnetoresistance (MR), 78%, is observed at 2 K on the ab plane of the diamagnetic RuSb2+ semiconductor. On the ac plane, MR is 44% at 2 K, and about 7% at 300 K. MR at different temperatures do not follow the Kohler’s rule. It suggests that the multiband effect plays a role on the carrier transportation. RuSb2+ is a semiconductor with both positive and negative carriers. The quantum interference effect with the weak localization correction lies behind the high positive MR at low temperature. Judged from the ultraviolet–visible spectra, it has a direct band gap of 1.29 eV. The valence band is 0.39 eV below the Fermi energy. The schematic energy band structure is proposed based on experimental results.

Experimental interference of uncorrelated photons

The distinguishing of the multiphoton quantum interference effect from the classical one forms one of the most important issues in modern quantum mechanics and experimental quantum optics. For a long time, the two-photon interference (TPI) of correlated photons has been recognized as a pure quantum effect that cannot be simulated with classical lights. In the meantime, experiments have been carried out to investigate the classical analogues of the TPI. In this study, we conduct TPI experiments with uncorrelated photons with different center frequencies from a luminescent light source, and we compare our results with the previous ones of correlated photons. The observed TPI fringe can be expressed in the form of three phase terms related to the individual single-photon and two-photon states, and the fringe pattern is strongly affected by the two single-photon-interference fringes and also by their visibilities. With the exception of essential differences such as valid and accidental coincidence events within a given resolving time and the two-photon spectral bandwidth, the interference phenomenon itself exhibits the same features for both correlated and uncorrelated photons in the single-photon counting regime.