The aim here is to figure out how to compute the Green’s function for an infinite system consisting of a finite subsystem such as a quantum dot or a molecule that is coupled to an infinite subsystem such as a carbon nanotube, graphene sheet, or a generic surface. The aim is to find a computationally tractable method that gives the correct Green’s function and thus time evolution for such a syst...

A split Cooper pair is a natural source for entangled electrons which is a basic ingredient for quantum information in the solid state. We report an experiment on a superconductor-graphene double quantum dot (QD) system, in which we observe Cooper pair splitting (CPS) up to a CPS efficiency of ∼10%. With bias on both QDs, we are able to detect a positive conductance correlation across the two d...

Phototransistors In article number 2205679, Peiguang Yan, Zhenhua Sun, and co-workers report a near-infrared phototransistor with benign light-irradiance adaptability using vertically stacking graphene/lead sulfide quantum dots/graphene heterojunction as the conductive channel. The dynamic trapping detrapping processes in dot film enable inhabitation or potentiation of photoresponse, based on w...

Graphene1 is the physical realization of many fundamental concepts and phenomena in solid-state physics2. However, in the list of graphene’s many remarkable properties3–6, superconductivity is notably absent. If it were possible to find a way to induce superconductivity, it could improve the performance and enable more efficient integration of a variety of promising device concepts including na...

Density functional calculations are performed to study the electronic structure of recently proposed graphene/graphane based core/shell quantum dots, which have a type I band alignment and exhibit quantized carrier energy levels. Strong confinement is robust with shell thickness. The bandgap, band offset, and the number of confined carrier orbitals with different size and geometry are determine...

We investigate the electronic transport through a single-level quantum-dot which is capacitively coupled to a charge-qubit. By employing the method of nonequilibrium Green's functions, we calculate the electric current through quantum dot at finite bias voltages. The Green's functions and self-energies of the system are calculated perturbatively and self-consistently to the second order of inte...

Related Articles Magnetoresistance in graphene-based ferromagnetic/ferromagnetic barrier/superconductor junction J. Appl. Phys. 111, 123908 (2012) Josephson comparator with modified dynamic behavior for improved sensitivity J. Appl. Phys. 111, 123901 (2012) Effect of thermal inhomogeneity for terahertz radiation from intrinsic Josephson junction stacks of Bi2Sr2CaCu2O8+δ Appl. Phys. Lett. 100, ...

A cooled scanning probe microscope (SPM) is an ideal tool to image electronic motion in graphene: the SPM tip acts as a scanning gate, which interacts with the electron gas below. We introduce the technique using our group’s previous work on imaging electron flow from a quantum point contact in a GaAs 2DEG and tuning an InAs quantum dot in an InAs/InP nanowire. Carriers in graphene have very di...

Infrared photodetectors (IRPDs) have become important devices in various applications such as night vision, military missile tracking, medical imaging, industry defect imaging, environmental sensing, and exoplanet exploration. Mature semiconductor technologies such as mercury cadmium telluride and III–V material-based photodetectors have been dominating the industry. However, in the last few de...