相关论文: A quantum point contact for neutral atoms

In transport experiments the quantum nature of matter becomes directly evident when changes in conductance occur only in discrete steps, with a size determined solely by Planck's constant h. The observations of quantized steps in the…

Simulation of Electron Transport through two dimensional(2D) waveguide using Quantum Transport Boundary Method (QTBM) is done. Specifically, as an example the results of modeling L-shaped contact for a rectangular waveguide are presented.…

A versatile miniature de Broglie waveguide is formed by two parallel current-carrying wires in the presence of a uniform bias field. We derive a variety of analytical expressions to describe the guide and present a quantum theory to show…

Coupling quantum emitters and nanostructures, in particular cold atoms and waveguides, has recently raised a large interest due to unprecedented possibilities of engineering light-matter interactions. However, the implementation of these…

Here, we employ a numerical approach to investigate the transport and conductance characteristics of a quantum point contact. A quantum point contact is a narrow constriction of a width comparable to the electron wavelength defined in a…

We consider the conductance of a quantum tube connected to a metallic contact. The number of angular momentum states that the tube can support depends on the strength of the radial confinement. We calculate the transmission coefficients…

We study the transport through a quantum dot coupled to two leads by single-mode point contacts. The linear conductance is calculated analytically as a function of a gate voltage and temperature T in the case when transmission coefficients…

Signatures of quantum transport are expected to quickly vanish as dissipation is introduced in a system. This dissipation can take several forms, including that of particle loss, which has the consequence that the total probability current…

Short length quantum wires (quantum contacts) exhibit a conductance structure at the value of conductance close to 0.7 \times 2e^2/h. The structure is also called the conductance anomaly. In longer contacts the structure evolves to the…

We propose and investigate a new type of optical waveguide made by an array of atoms without involving conventional Bragg scattering or total internal reflection. A finite chain of atoms collectively coupled through their intrinsic…

Lithographically fabricated circuit patterns can provide magnetic guides and microtraps for cold neutral atoms. By combining several such structures on the same ceramic substrate, we have realized the first ``atom chips'' that permit…

We present a scanning probe microscopy technique for spatially resolving transport in cold atomic gases, in close analogy with scanning gate microscopy in semiconductor physics. The conductance of a quantum point contact connected to two…

The exact expression for the phase-dependent linear conductance of a weakly damped superconducting quantum point contact is obtained. The calculation is performed by summing up the complete perturbative series in the coupling between the…

Coherent electronic transport through individual molecules is crucially sensitive to quantum interference. Using exact diagonalization techniques, we investigate the zero-bias and zero-temperature conductance through $\pi$-conjugated…

We consider a transmission of electrons through a two-dimensional ballistic point contact in the low-conductance regime below the 0.7-anomaly. The scattering of electrons by Friedel oscillations of charge density results in a contribution…

The electrical transport properties of atomic-scale conductors are reviewed, with an emphasis on the relations of this problem with studies on quantum size effects in metallic clusters. A brief introduction is given of the natural formalism…

Charge detection utilizing a highly biased quantum point contact has become the most effective probe for studying few electron quantum dot circuits. Measurements on double and triple quantum dot circuits is performed to clarify a back…

It is known that the conductance of a quantum point contact is quantized in units of $2e^2/h$ and this quantization is destroyed by a non-adiabatic scatterer in the point contact, due to backscattering. Recently, it was shown [Phys. Rev.…

We study the current through a quantum wire side coupled to a quantum dot, and compare it with the case of an embedded dot. The system is modeled by the Anderson Hamiltonian for a linear chain, with one atom either coupled to (side-dot) or…

We fabricated strongly confined Schottky-gated quantum point contacts by etching Si/SiGe heterostructures and observed intriguing conductance quantization in units of approximately 1e2/h. Non-linear conductance measurements were performed…