Related papers: Locally induced quantum interference in scanning g…
We perform scanning gate experiments on ballistic constrictions in the presence of small perpendicular magnetic fields. The constrictions form the entrance and exit of a circular gate-defined ballistic stadium. Close to constrictions we…
Combining Scanning Gate Microscopy (SGM) experiments and simulations, we demonstrate low temperature imaging of electron probability density $|\Psi|^{2}(x,y)$ in embedded mesoscopic quantum rings (QRs). The tip-induced conductance…
We study the conductance of an electron interferometer formed in a two dimensional electron gas between a nanostructured quantum contact and the charged tip of a scanning gate microscope. Measuring the conductance as a function of the tip…
Tailored electrostatic potentials are the foundation of scanning gate microscopy. We present several aspects of the tip-induced potential on the two-dimensional electron gas. First, we give methods on how to estimate the size of the…
We present a detailed experimental study on the electrostatic interaction between a quantum dot and the metallic tip of a scanning force microscope. Our method allowed us to quantitatively map the tip-induced potential and to determine the…
We study the conductance $g$ of an electron interferometer created in a two dimensional electron gas between a nanostructured contact and the depletion region induced by the charged tip of a scanning gate microscope. Using non-interacting…
We measure the conductance of a quantum point contact (QPC) while the biased tip of a scanning probe microscope induces a depleted region in the electron gas underneath. At finite magnetic field we find plateaus in the real-space maps of…
Using the tip of a scanning probe microscope as a local electrostatic gate gives access to real space information on electrostatics as well as charge transport at the nanoscale, provided that the tip-induced electrostatic potential is well…
Traditionally, the understanding of quantum transport, coherent and ballistic1, relies on the measurement of macroscopic properties such as the conductance. While powerful when coupled to statistical theories, this approach cannot provide a…
With an atomic force microscope a ring geometry with self-aligned in-plane gates was directly written into a GaAs/AlGaAs-heterostructure. Transport measurements in the open regime show only one transmitting mode and Aharonov-Bohm…
An open resonator fabricated in a two-dimensional electron gas is used to explore the transition from strongly invasive scanning gate microscopy to the perturbative regime of weak tip-induced potentials. With the help of numerical…
New experiments are presented on the transmission of electron waves through a 2DEG (2 dimensional electron gas) ring with a gate on top of one of the branches. Magnetoconductance oscillations are observed, and the phase of the Aharanov-Bohm…
In scanning gate microscopy, where the tip of a scanning force microscope is used as a movable gate to study electronic transport in nanostructures, the shape and magnitude of the tip-induced potential are important for the resolution and…
We investigate the effect of a scanning gate tip in the nonlinear quantum transport properties of nanostructures. Generally, we predict that the symmetry of the current-voltage characteristic in reflection-symmetric samples is broken by a…
The Aharonov-Bohm (AB) interference patterns in ring-shaped conductors are usually dominated by random features. The amplitude of the oscillations is random from sample to sample and from point to point on the magnetic field axis owing to…
We demonstrate a scanning gate grid measurement technique consisting in measuring the conductance of a quantum point contact (QPC) as a function of gate voltage at each tip position. Unlike conventional scanning gate experiments, it allows…
We use the Aharonov-Bohm effect in a four-terminal ring based on a Ga[Al]As heterostructure for the measurement of the relative transmission phase. In each of the two interfering paths we induce a quantum dot. The number of electrons in the…
This article reports on tunable electron backscattering investigated with the biased tip of a scanning force microscope. Using a channel defined by a pair of Schottky gates, the branched electron flow of ballistic electrons injected from a…
We present detailed simulations addressing recent electronic interference experiments, where a metallic gate is used to locally modify the Fermi wave-length of the charge carriers. Our numerical calculations are based on a solution of the…
Using the recursive Green's function technique, we study the coherent electron conductance of a quantum point contact in the presence of a scanning probe microscope tip. Images of the coherent fringe inside a quantum point contact for…