Do you want to publish a course? Click here

The Behavior of Electronic Interferometers in the Non-Linear Regime

102   0   0.0 ( 0 )
 Added by Izhar Neder
 Publication date 2008
  fields Physics
and research's language is English




Ask ChatGPT about the research

We investigate theoretically the behavior of the current oscillations in an electronic Mach-Zehnder interferometer (MZI) as a function of its source bias. Recently, The MZI interference visibility showed an unexplained lobe pattern behavior with a peculiar phase rigidity. Moreover, the effect did not depend on the MZI paths difference. We argue that these effects may be a new many-body manifestation of particle-wave duality of quantum mechanics. When biasing the interferometer sources beyond the linear response regime, quantum shot-noise (a particle phenomena) must affect the interference pattern of the electrons that creates it, as a result from a simple invariance argument. An approximate solution of the interacting Hamiltonian indeed shows that the interference visibility has a lobe pattern with applied bias with a period proportional to the average path length and independent of the paths difference, together with a phase rigidity.



rate research

Read More

The self-consistent quantum-electrostatic (also known as Poisson-Schrodinger) problem is notoriously difficult in situations where the density of states varies rapidly with energy. At low temperatures, these fluctuations make the problem highly non-linear which renders iterative schemes deeply unstable. We present a stable algorithm that provides a solution to this problem with controlled accuracy. The technique is intrinsically convergent including in highly non-linear regimes. We illustrate our approach with (i) a calculation of the compressible and incompressible stripes in the integer quantum Hall regime and (ii) a calculation of the differential conductance of a quantum point contact geometry. Our technique provides a viable route for the predictive modeling of the transport properties of quantum nanoelectronics devices.
Systems in the dispersive regime of cavity quantum electrodynamics (QED) are approaching the limits of validity of the dispersive approximation. We present a model which takes into account nonlinear corrections to the dressing of the atom by the field. We find that in the presence of pure dephasing, photons populating the cavity act as a heat bath on the atom, inducing incoherent relaxation and excitation. These effects are shown to reduce the achievable signal-to-noise ratio in cavity QED realizations where the atom is measured indirectly through cavity transmission and in particular in circuit QED.
In a series of recent papers anomalous Hall and Nernst effects have been theoretically discussed in the non-linear regime and have seen some early success in experiments. In this paper, by utilizing the role of Berry curvature dipole, we derive the fundamental mathematical relations between the anomalous electric and thermoelectric transport coefficients in the non-linear regime. The formulae we derive replace the celebrated Wiedemann-Franz law and Mott relation of anomalous thermoelectric transport coefficients defined in the linear response regime. In addition to fundamental and testable new formulae, an important byproduct of this work is the prediction of nonlinear anomalous thermal Hall effect which can be observed in experiments.
We investigate the spectral characteristics of spin torque oscillator (STO) excited by the spin Hall-induced spin current. We observe that the modest spin current injection triggers the conventional single peak oscillating behavior of STO. As the spin current is further increased to enter the non-linear regime, we find the transition of the spectrum from a single peak to multipeak structure whose frequency spacing is constant. This behavior can be primarily explained by the extremely broadened peak of the STO, which is accompanied by the frequency-dependent filtering by the transmission line. To explain the observation more quantitatively, we also discuss that the multipeak may reflect the characteristics of the intrinsic dynamics of STO in the non-linear regime.
A fabrication method for electronic quantum Hall Fabry-Perot interferometers (FPI) is presented. Our method uses a combination of e-beam lithography and low-damage dry-etching to produce the FPIs and minimize the excitation of charged traps or deposition of impurities near the device. Optimization of the quantum point contacts (QPC) is achieved via systematically varying the etch depth and monitoring the device resistance between segmented etching sessions. The etching is stopped when a desired value of resistance is obtained. Finer control of interference trajectories is obtained by the gate metallized inside the etched area by e-beam evaporation. Our approach allows for a control of the delicate potential bending near the quantum well by tuning the confining potential of the quantum point contacts.
comments
Fetching comments Fetching comments
Sign in to be able to follow your search criteria
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا