The Fermionic Hanbury Brown and Twiss Experiment

Henny, M.; Oberholzer, S.; Strunk, Christoph; Heinzel, T.; Ensslin, Klaus; Holland, M.; Schönenberger, Christian

doi:10.1126/science.284.5412.296

Cited by 413 publications

(447 citation statements)

References 30 publications

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“…Nevertheless, the equilibrium noise is important, if only to calibrate experiments and as a simple test for theoretical discussions. Experimentally, a careful study of thermal noise in a multi-terminal structure (a quantum Hall bar with a constriction) was recently performed by Henny et al [12]. Within the experimental accuracy, the results agree with the theoretical predictions.…”

Section: General Expressions For Noisesupporting

confidence: 75%

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Shot noise in mesoscopic conductors

2000

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Theoretical and experimental work concerned with dynamic fluctuations has developed into a very active and fascinating subfield of mesoscopic physics. We present a review of this development focusing on shot noise in small electric conductors. Shot noise is a consequence of the quantization of charge. It can be used to obtain information on a system which is not available through conductance measurements. In particular, shot noise experiments can determine the charge and statistics of the quasiparticles relevant for transport, and reveal information on the potential profile and internal energy scales of mesoscopic systems. Shot noise is generally more sensitive to the effects of electron-electron interactions than the average conductance. We present a discussion based on the conceptually transparent scattering approach and on the classical Langevin and BoltzmannLangevin methods; in addition a discussion of results which cannot be obtained by these methods is provided. We conclude the review by pointing out a number of unsolved problems and an outlook on the likely future development of the field.

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Section: General Expressions For Noisesupporting

confidence: 75%

“…The double-barrier problem is also relevant for quantum wells, which are two-or threedimensional structures 12 , consisting of two planar (linear in two dimensions) potential barriers. Of interest is transport in the direction perpendicular to the barriers (across the quantum well, axis z).…”

Section: Resonant Tunnel Barriersmentioning

confidence: 99%

Shot noise in mesoscopic conductors

2000

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“…The demonstration of entanglement and multiparticle interference with such wave packets would set the stage for quantum-technology applications such as quantum information processing [1]. Various theoretical proposals [2][3][4][5][6][7] and experimental realizations [8][9][10][11][12][13][14][15][16][17] employ quantum Hall edge states [18] as electron waveguides. The group velocity and dispersion relation of edge states are important parameters for understanding and controlling electron wave packet propagation.…”

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confidence: 99%

Time-of-Flight Measurements of Single-Electron Wave Packets in Quantum Hall Edge States

et al. 2016

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We report time-of-flight measurements on electrons traveling in quantum Hall edge states. Hot-electron wave packets are emitted one per cycle into edge states formed along a depleted sample boundary. The electron arrival time is detected by driving a detector barrier with a square wave that acts as a shutter. By adding an extra path using a deflection barrier, we measure a delay in the arrival time, from which the edgestate velocity v is deduced. We find that v follows 1=B dependence, in good agreement with theẼ ×B drift. The edge potential is estimated from the energy dependence of v using a harmonic approximation. DOI: 10.1103/PhysRevLett.116.126803 Electronic analogues of photonic quantum-optics experiments, so-called "electron quantum optics," can be performed using the beams of single-electron wave packets. The demonstration of entanglement and multiparticle interference with such wave packets would set the stage for quantum-technology applications such as quantum information processing [1]. Various theoretical proposals [2][3][4][5][6][7] and experimental realizations [8][9][10][11][12][13][14][15][16][17] employ quantum Hall edge states [18] as electron waveguides. The group velocity and dispersion relation of edge states are important parameters for understanding and controlling electron wave packet propagation. For edge magnetoplasmons, the velocity can be deduced by time-of-flight measurements with gate pulses [19][20][21][22]. Such direct velocity measurements have been difficult with electron wave packets because gate pulses would also affect the background Fermi sea. Previous experiments [14,23,24] use other types of electron-transport data to estimate the electron velocity. Furthermore, electronelectron interactions can cause the formation of multiple collective modes traveling at different velocities, leading to decoherence [14,17,25]. In order to perform the measurements of bare group velocity by time-resolved methods, we need a robust edge-state waveguide system where the interactions between the transmitted electrons and other electrons in the background can be suppressed.In this Letter, we demonstrate an experimental method for probing the bare edge-state velocity of electrons traveling in a depleted edge of a two-dimensional system. Electrons are emitted from a tunable-barrier single-electron pump [26][27][28] approximately 100 meV above the Fermi energy [13,29]. These electrons are injected into an edge where the background two-dimensional electron gas (2DEG) is depleted to avoid the influence of electron-electron interactions. The arrival time of these wave packets is detected by an energyselective detector barrier with a picosecond resolution [13,16]. The travel length between the source and detector is switched by a deflection barrier. The time of flight of the extra path is measured as a delay in the arrival time at the detector [30]. The edge-state velocity is calculated from the length of the extra path and the time of flight. We find that the edge-state velocity is inversely propor...

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“…Attempts to measure the expected negative correlation in a beam of free electrons have not been successful yet, mainly because of the low particle density in such a beam. The HBT experiment for fermions has recently been carried out in two independent experiments based on semiconductor devices [7]. Theoretically, these experiments and other multiterminal correlation experiments have been considered before [4,[8][9][10].…”

mentioning

confidence: 99%

The Hanbury Brown and Twiss experiment with fermions

Oberholzer

Henny

Strunk

et al. 2000

Physica E: Low-dimensional Systems and Nanostructures

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We realized an equivalent Hanbury Brown and Twiss experiment for a beam of electrons in a two dimensional electron gas in the quantum Hall regime. A metallic split gate serves as a tunable beam splitter which is used to partition the incident beam into transmitted and reflected partial beams. The current fluctuations in the reflected and transmitted beam are fully anticorrelated demonstrating that fermions tend to exclude each other (antibunching). If the occupation probability of the incident beam is lowered by an additional gate, the anticorrelation is reduced and disappears in the classical limit of a highly diluted beam. Keywords: quantum statistics; noise; correlationThe first quantum statistical measurements were carried out with photons by Hanbury Brown and Twiss (HBT) in the 1950s. In a pioneering experiment HBT determined the size of astronomical radio sources by measuring the spatial coherence of the emitted radiation from correlations between intensity fluctuations at two different locations [1]. In a subsequent optical table-top experiment, they tested their idea by measuring intensity correlations for visible light: the light beam of a Hg vapor lamp (IN) was split into a transmitted (T) and a reflected beam (R) (see Fig. 1). The equal-time intensity correlations between the two separated photon streams was found to be positive (bunching) [2,3]. This is a generic property of particles 1 To whom correspondence should be addressed: E-mail: stefan.oberholzer@unibas.ch obeying Bose-Einstein statistics. In contrast to bosons, a negative correlation or 'antibunching' is expected for fermions, because fermions have to exclude each other due to the Pauli principle.In general, the time dependent number of particles n(t) detected during a certain time interval exhibits fluctuations ∆n(t) = n(t) − n around the average n , called shot noise. Shot noise in the electrical current is caused by the discreteness of the electron charge and has been extensively studied in submicrometer-sized nanostructures [4,5]. In a HBT type experiment, not the fluctuations in a single beam are measured, but the correlation between fluctuations in the transmitted (T) and reflected (R) beam originating from a beam splitter (see Fig. 1). If the incident beam (IN) is not prepared at a single-particle level, but shows intensity

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The Fermionic Hanbury Brown and Twiss Experiment

Cited by 413 publications

References 30 publications

Shot noise in mesoscopic conductors

Shot noise in mesoscopic conductors

Time-of-Flight Measurements of Single-Electron Wave Packets in Quantum Hall Edge States

The Hanbury Brown and Twiss experiment with fermions

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