Low-field quantum Hall transport in an electron Fabry-Perot interferometer: Dependence of constriction filling on front-gate voltage

Lin, Ping; Goldman, V. J.

doi:10.1103/physrevb.78.245322

Cited by 3 publications

(5 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…28 The aperiodic peaks or dips in Fig. 1, spaced by ~0.03 T, are attributed to disorder-assisted tunneling outside the constrictions; similar ubiquitous mesoscopic fluctuations are also seen in the same device at lower magnetic fields 27 and in quantum antidots. That the aperiodic peaks originate outside of the island is evidenced by their different response to front gates of the left and right constrictions.…”

mentioning

confidence: 70%

See 1 more Smart Citation

Electron interferometry in the quantum Hall regime: Aharonov-Bohm effect of interacting electrons

Lin

Goldman

2009

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

An apparent h/fe Aharonov-Bohm flux period, where f is an integer, has been reported in coherent quantum Hall devices. Such sub-period is not expected for non-interacting electrons and thus is thought to result from interelectron Coulomb interaction. Here we report experiments in a Fabry-Perot interferometer comprised of two wide constrictions enclosing an electron island. By carefully tuning the constriction front gates, we find a regime where interference oscillations with period h/2e persist throughout the transition between the integer quantum Hall plateaus 2 and 3, including half-filling. In a large quantum Hall sample, a transition between integer plateaus occurs near half-filling, where the bulk of the sample becomes delocalized and thus dissipative bulk current flows between the counterpropagating edges ("backscattering"). In a quantum Hall constriction, where conductance is due to electron tunneling, a transition between forward-and back-scattering is expected near the half-filling. In our experiment, neither period nor amplitude of the oscillations show a discontinuity at half-filling, indicating that only one interference path exists throughout the transition. We also present experiments and an analysis of the front-gate dependence of the phase of the oscillations. The results point to a single physical mechanism of the observed conductance oscillations: Aharonov-Bohm interference of interacting electrons in quantum Hall regime.The Aharonov-Bohm effect demonstrates the primacy of the potentials, rather than fields in quantum mechanics. Electron interaction usually does not affect the e h / Aharonov-Bohm flux period observed in conductance of normal metal and semiconductor rings with two leads. The situation is more complex in quantum Hall devices. An apparent e f h / Aharonov-Bohm flux period, where f is the integer quantum Hall effect (QHE) filling in the constrictions, has been reported in quantum antidot 4,5 and Fabry-Perot interferometer 6-8 devices. In quantum antidots, the closed AharonovBohm path follows an equipotential around the lithographically-defined potential hill in the twodimensional (2D) electron plane. In interferometer devices, the interference path follows an equipotential at device's edges, and is closed by two tunneling links.The experiments are done in a uniform magnetic field, so that a well-defined interference path enclosing an area is needed to translate the field into flux. This Aharonov-Bohm sub-period is accompanied by an e charge period as a function of a gate voltage, and is not affected by the 2D bulk filling outside the device. In quantum antidots, previously reported e h 2 / period 9,10 was tentatively attributed to spin-splitting of a Landau level. However, subsequent work has concluded that no model of non-interacting electrons can consistently explain this sub-period. 11,12 On the other hand, it seems apparent that the strong interelectron Coulomb interaction, present in

show abstract

mentioning

confidence: 70%

“…1, was described previously. 26,27 The etch trenches define two 1.2 m-wide constrictions, which separate an approximately circular electron island from the 2D bulk. Tunneling occurs in the two constrictions, thus forming a Fabry-Perot interferometer.…”

mentioning

confidence: 99%

Electron interferometry in the quantum Hall regime: Aharonov-Bohm effect of interacting electrons

Lin

Goldman

2009

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

show abstract

“…1͑a͔͒ ͑Ref. 15,16,20 The results reported here suggest that, by an accurate choice of the working point, the latter devices could be easily used as OR and XOR gates. 1͑d͒.…”

Section: -5mentioning

confidence: 77%

Quantum Hall Fabry–Pérot interferometer: Logic gate responses

Bellucci

Onorato

2010

Journal of Applied Physics

View full text Add to dashboard Cite

Scanning Fabry-Pérot interferometer with largely tuneable free spectral range for high resolution spectroscopy of single quantum dots Rev. Sci. Instrum. 82, 073103 (2011); 10.1063/1.3601016 Quantum nanojunctions as spintronic logic operators: Gate response in a two input ballistic interferometer Fabry-Pérot interferometer utilized for displacement measurement in a large measuring range Rev. Sci. Instrum. 81, 093102 (2010); 10.1063/1.3480551 Broadband precision wavelength meter based on a stepping Fabry-Pérot interferometer Rev. Sci. Instrum. 75, 3318 (2004);We discuss the electron transport through a quantum Hall Fabry-Pérot interferometer ͑QHFPI͒ obtained with two quantum point contacts ͑QPCs͒ in series along a ballistic quantum wire by focusing on the effects due to quantum interference and to quantum Hall effect. We calculate the conductance-energy and conductance-magnetic field characteristics as functions of the geometrical parameters and gate voltages. QHFPI may be utilized in designing electronic logic gates: XOR and OR ͑NOR and XNOR͒ gates responses are investigated. The width of each QPC is modulated by metallic electrodes where two gate voltages, namely, V a and V b , are applied. Those external voltages are treated as the two inputs of the gates. After fixing appropriately the working Fermi energy, the magnetic field strength, and the distance between the barriers, a low output Hall current ͑0͒ ͑in the logical sense͒ appears just if both inputs are low ͑0͒, while a high output Hall current ͑1͒ results otherwise. It clearly demonstrates the OR gate behavior. By changing the parameters, a XOR gate can be produced, where a high output current ͑1͒ appears, when just one of the two inputs is low ͑0͒, while a low output current ͑0͒ results if both inputs are low ͑0͒ or high ͑1͒.

show abstract

“…This allows to determine the saddle point density from the R XX ͑B͒ and R XY ͑B͒ magnetotransport; a systematic study of quantum Hall transport and analysis were reported for a similar sample in Ref. 41. The local Landau level filling = hn / eB is proportional to the local electron density n; accordingly the constriction C is lower than the bulk B in a given B.…”

Section: Resultsmentioning

confidence: 95%

“…This allows to determine the saddle point density from the ) (B R XX and ) (B R XY magnetotransport; a systematic study of quantum Hall transport and analysis were reported for a similar sample in Ref. 41 . In this device, the island center density is estimated to be close to the bulk B n at 0 FG V , the constriction -island center density difference is ~20%.…”

Section: Resultsmentioning

confidence: 99%

Superperiods in interference ofe/3Laughlin quasiparticles encircling filling 2/5 fractional quantum Hall island

Lin

Goldman

2009

Phys. Rev. B

Self Cite

View full text Add to dashboard Cite

We report experiments in a large, 2.5 m diameter Fabry-Perot quantum Hall interferometer with two tunneling constrictions. Interference fringes are observed as conductance oscillations as a function of applied magnetic field ͑the Aharonov-Bohm flux through the electron island͒ or a global backgate voltage ͑electronic charge in the island͒. Depletion is such that in the fractional quantum Hall regime, filling 1/3 current-carrying chiral edge channels pass through constrictions when the island filling is 2/5. The interferometer device is calibrated with fermionic electrons in the integer quantum Hall regime. In the fractional regime, we observe magnetic flux and charge periods 5h / e and 2e, respectively, corresponding to creation of ten e / 5 Laughlin quasiparticles in the island. These results agree with our prior report of the superperiods in a much smaller interferometer device. The observed experimental periods are interpreted as imposed by anyonic statistical interaction of fractionally charged quasiparticles.

show abstract

Low-field quantum Hall transport in an electron Fabry-Perot interferometer: Dependence of constriction filling on front-gate voltage

Cited by 3 publications

References 42 publications

Electron interferometry in the quantum Hall regime: Aharonov-Bohm effect of interacting electrons

Electron interferometry in the quantum Hall regime: Aharonov-Bohm effect of interacting electrons

Quantum Hall Fabry–Pérot interferometer: Logic gate responses

Superperiods in interference ofe/3Laughlin quasiparticles encircling filling 2/5 fractional quantum Hall island

Contact Info

Product

Resources

About