Related papers: Conductance quantization and shot noise of a doubl…
A gate-defined quantum dot in an InAs nanowire is fabricated on top of a quantum point contact realized in a two-dimensional electron gas. The strong coupling between these two quantum devices is used to perform time-averaged as well as…
Shot noise and higher current moments T_M=<Tr (t^+t)^M> are studied within the Anderson model of disordered conductors in dimensions d= 2, 3 and 4. Here t denotes a transmission matrix. We calculate the conductance G=T_1, shot noise…
We observed the recently predicted quantum suppression of dynamical Coulomb blockade on short coherent conductors by measuring the conductance of a quantum point contact embedded in a tunable on-chip circuit. Taking advantage of the circuit…
Transport properties of graphene - superconductor junction has been studied extensively to understand the interplay of the relativistic Dirac quasiparticles and superconductivity. Though shot noise measurements in graphene has been…
We present measurements of transport through two tunnel-coupled quantum dots of different sizes connected in series in a strong, variable, perpendicular magnetic field. Double dot conductance was measured both as a function of magnetic…
We compute the shot noise in ballistic and disordered Fe/MgO/Fe tunnel junctions by a wave function-matching method. For tunnel barriers with no more than 5 atomic layers we find a suppression of the Fano factor as a function of the…
The current noise in a quantum dot coupled to two leads is investigated in the Kondo regime with and without the influence of magnetic fields by employing a finite-$U$ slave-boson mean field theory to calculate the current-current…
We investigate shot noise at {\it finite temperatures} induced by the quasi-particle tunneling between fractional quantum Hall (FQH) edge states. The resulting Fano factor has the peak structure at a certain bias voltage. Such a structure…
We theoretically examine the transport through an Aharonov-Bohm ring with an embedded quantum dot (QD), the so-called QD interferometer, to address two controversial issues regarding the shape of the Coulomb peaks and measurement of the…
The electrical conductance of atomic metal contacts represents a powerful tool to detect nanomagnetism. Conductance reflects magnetism through anomalies at zero bias -- generally with Fano lineshapes -- due to the Kondo screening of the…
We analyze decoherence of an electron in a double-dot due to the interaction with acoustic phonons. For large tunneling rates between the quantum dots, the main contribution to decoherence comes from the phonon emission relaxation…
Highly-doped graphene samples show the conductance reduced and the shot-noise power enhanced compared to standard ballistic systems in two-dimensional electron gas. These features can be understood within a model assuming incoherent…
We study the conductance and current noise of a superconductor/ferromagnet (S/F) single channel Quantum Point Contact (QPC) as a function of the QPC bias voltage, using a scattering approach. We show that the Spin-Dependence of Interfacial…
We describe a phenomenological model for the conductance feature near $0.7 \times 2e^2/h$ that occurs in quantum point contacts. We focus on the transconductance at finite source-drain bias and contrast our model with the results expected…
We have investigated shot noise in a 6-nm-diameter, semiconducting multiwalled carbon nanotube FET at 4.2 K over the frequency range 600 - 950 MHz. We find a transconductance of 3 - 3.5 $\mu$S for optimal positive and negative source-drain…
Quantum point contact or QPC -- a constriction in a semiconducting two-dimensional (2D) electron system with a quantized conductance -- has been found as the building block of novel spintronic, and topological electronic circuits. They can…
The transmission of conductance modes in atom-size gold contacts is investigated by simultaneously measuring conductance and shot noise. The results give unambiguous evidence that the current in the smallest gold contacts is mostly carried…
Besides the usual conductance plateaus at multiples of 2e2/h, quantum point contacts typically show an extra plateau at ~ 0.7(2e2/h), believed to arise from electron-electron interactions that prohibit the two spin channels from being…
We investigate the transmission of electrons through a quantum point contact by using a quasi-one-dimensional model with a local bound state below the band bottom. While the complete transmission in lower channels gives rise to plateaus of…
We consider the effects of interactions on the edges of ``double" quantum spin Hall insulators (DQSHIs), motivated by recent experiments on moir\'e twisted metal dichalcogenides. Without interactions, a DQSHI can be understood as two copies…