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Quantum pump driven fermionic Mach-Zehnder interferometer

Chung, S. -W. V.; Moskalets, M. and Samuelsson, Peter LU (2007) In Physical Review B (Condensed Matter and Materials Physics) 75(11).
Abstract
We have investigated the characteristics of the currents in a pump driven fermionic Mach-Zehnder interferometer. The system is implemented in a conductor in the quantum Hall regime, with the two interferometer arms enclosing an Aharonov-Bohm flux Phi. Two quantum point contacts with transparency modulated periodically in time drive the current and act as beam splitters. The current has a flux-dependent part I-(Phi) as well as a flux-independent part I-(0). Both current parts show oscillations as a function of frequency on the two scales determined by the lengths of the interferometer arms. In the nonadiabatic, high-frequency regime I-(Phi) oscillates with a constant amplitude while the amplitude of the oscillations of I-(0) increases... (More)
We have investigated the characteristics of the currents in a pump driven fermionic Mach-Zehnder interferometer. The system is implemented in a conductor in the quantum Hall regime, with the two interferometer arms enclosing an Aharonov-Bohm flux Phi. Two quantum point contacts with transparency modulated periodically in time drive the current and act as beam splitters. The current has a flux-dependent part I-(Phi) as well as a flux-independent part I-(0). Both current parts show oscillations as a function of frequency on the two scales determined by the lengths of the interferometer arms. In the nonadiabatic, high-frequency regime I-(Phi) oscillates with a constant amplitude while the amplitude of the oscillations of I-(0) increases linearly with frequency. The flux-independent part I-(0) is insensitive to temperature while the flux-dependent part I-(Phi) is exponentially suppressed with increasing temperature. We also find that for low amplitude, adiabatic pumping rectification effects are absent for semitransparent beam splitters. Inelastic dephasing is introduced by coupling one of the interferometer arms to a voltage probe. For a long charge relaxation time of the voltage probe, giving a constant probe potential, I-(Phi) and the part of I-(0) flowing in the arm connected to the probe are suppressed with increased coupling to the probe. For a short relaxation time, with the potential of the probe adjusting instantaneously to give zero time-dependent current at the probe, only I-(Phi) is suppressed by the coupling to the probe. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B (Condensed Matter and Materials Physics)
volume
75
issue
11
publisher
American Physical Society
external identifiers
  • wos:000245329600099
  • scopus:34047124235
ISSN
1098-0121
DOI
10.1103/PhysRevB.75.115332
language
English
LU publication?
yes
id
0b94a522-fb4b-4e7f-a096-d345dcf1b823 (old id 668374)
date added to LUP
2007-12-06 10:07:05
date last changed
2017-09-10 04:26:02
@article{0b94a522-fb4b-4e7f-a096-d345dcf1b823,
  abstract     = {We have investigated the characteristics of the currents in a pump driven fermionic Mach-Zehnder interferometer. The system is implemented in a conductor in the quantum Hall regime, with the two interferometer arms enclosing an Aharonov-Bohm flux Phi. Two quantum point contacts with transparency modulated periodically in time drive the current and act as beam splitters. The current has a flux-dependent part I-(Phi) as well as a flux-independent part I-(0). Both current parts show oscillations as a function of frequency on the two scales determined by the lengths of the interferometer arms. In the nonadiabatic, high-frequency regime I-(Phi) oscillates with a constant amplitude while the amplitude of the oscillations of I-(0) increases linearly with frequency. The flux-independent part I-(0) is insensitive to temperature while the flux-dependent part I-(Phi) is exponentially suppressed with increasing temperature. We also find that for low amplitude, adiabatic pumping rectification effects are absent for semitransparent beam splitters. Inelastic dephasing is introduced by coupling one of the interferometer arms to a voltage probe. For a long charge relaxation time of the voltage probe, giving a constant probe potential, I-(Phi) and the part of I-(0) flowing in the arm connected to the probe are suppressed with increased coupling to the probe. For a short relaxation time, with the potential of the probe adjusting instantaneously to give zero time-dependent current at the probe, only I-(Phi) is suppressed by the coupling to the probe.},
  author       = {Chung, S. -W. V. and Moskalets, M. and Samuelsson, Peter},
  issn         = {1098-0121},
  language     = {eng},
  number       = {11},
  publisher    = {American Physical Society},
  series       = {Physical Review B (Condensed Matter and Materials Physics)},
  title        = {Quantum pump driven fermionic Mach-Zehnder interferometer},
  url          = {http://dx.doi.org/10.1103/PhysRevB.75.115332},
  volume       = {75},
  year         = {2007},
}