1
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Shein-Lumbroso O, Liu J, Shastry A, Segal D, Tal O. Quantum Flicker Noise in Atomic and Molecular Junctions. PHYSICAL REVIEW LETTERS 2022; 128:237701. [PMID: 35749205 DOI: 10.1103/physrevlett.128.237701] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 05/02/2022] [Indexed: 06/15/2023]
Abstract
We report on a quantum form of electronic flicker noise in nanoscale conductors that contains valuable information on quantum transport. This noise is experimentally identified in atomic and molecular junctions and theoretically analyzed by considering quantum interference due to fluctuating scatterers. Using conductance, shot-noise, and flicker-noise measurements, we show that the revealed quantum flicker noise uniquely depends on the distribution of transmission channels, a key characteristic of quantum conductors. This dependence opens the door for the application of flicker noise as a diagnostic probe for fundamental properties of quantum conductors and many-body quantum effects, a role that up to now has been performed by the experimentally less-accessible shot noise.
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Affiliation(s)
- Ofir Shein-Lumbroso
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Junjie Liu
- Department of Chemistry and Centre for Quantum Information and Quantum Control, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
| | - Abhay Shastry
- Department of Chemistry and Centre for Quantum Information and Quantum Control, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
| | - Dvira Segal
- Department of Chemistry and Centre for Quantum Information and Quantum Control, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
- Department of Physics, 60 Saint George Street, University of Toronto, Toronto, Ontario M5S 1A7, Canada
| | - Oren Tal
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
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2
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Morawski F, Bejger M, Cuoco E, Petre L. Anomaly detection in gravitational waves data using convolutional autoencoders. MACHINE LEARNING: SCIENCE AND TECHNOLOGY 2021. [DOI: 10.1088/2632-2153/abf3d0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Abstract
As of this moment, 50 gravitational wave (GW) detections have been announced, thanks to the observational efforts of the LIGO-Virgo collaboration, working with the Advanced LIGO and the Advanced Virgo interferometers. The detection of signals is complicated by the noise-dominated nature of the data. Conventional approaches in GW detection procedures require either precise knowledge of the GW waveform in the context of matched filtering searches or coincident analysis of data from multiple detectors. Furthermore, the analysis is prone to contamination by instrumental or environmental artifacts called glitches which either mimic astrophysical signals or reduce the overall quality of data. In this paper, we propose an alternative generic method of studying GW data based on detecting anomalies. The anomalies we study are transient signals, different from the slow non-stationary noise of the detector. The anomalies presented in the manuscript are mostly based on the GW emitted by the mergers of binary black hole systems. However, the presented study of anomalies is not limited only to GW alone, but also includes glitches occurring in the real LIGO/Virgo dataset available at the Gravitational Waves Open Science Center. To search for anomalies we employ deep learning algorithms, namely convolutional autoencoders, which are trained on both simulated and real detector data. We demonstrate the capabilities of our deep learning implementation in the reconstruction of injected signals. We study the influence of the GW strength, defined in terms of matched filter signal-to-noise ratio, on the detection of anomalies. Moreover, we present the application of our method for the localization in time of anomalies in the studied time-series data. We validate the results of anomaly searches on real data containing confirmed gravitational wave detections; we thus prove the generalization capabilities of our method, towards detecting GWs unknown to our deep learning models during training.
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3
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Lee S, Hashisaka M, Akiho T, Kobayashi K, Muraki K. Cryogenic GaAs high-electron-mobility-transistor amplifier for current noise measurements. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:023910. [PMID: 33648138 DOI: 10.1063/5.0036419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
We show that a cryogenic amplifier composed of a homemade GaAs high-electron-mobility transistor (HEMT) is suitable for current-noise measurements in a mesoscopic device at dilution-refrigerator temperatures. The lower noise characteristics of our homemade HEMT lead to a lower noise floor in the experimental setup and enable more efficient current-noise measurement than is available with a commercial HEMT. We present the dc transport properties of the HEMT and the gain and noise characteristics of the amplifier. With the amplifier employed for current-noise measurements in a quantum point contact, we demonstrate the high resolution of the measurement setup by comparing it with that of the conventional one using a commercial HEMT.
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Affiliation(s)
- Sanghyun Lee
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Masayuki Hashisaka
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Takafumi Akiho
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Kensuke Kobayashi
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Koji Muraki
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
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4
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Tewari S, van Ruitenbeek J. Anomalous Nonlinear Shot Noise at High Voltage Bias. NANO LETTERS 2018; 18:5217-5223. [PMID: 29957997 PMCID: PMC6089497 DOI: 10.1021/acs.nanolett.8b02176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/26/2018] [Indexed: 06/08/2023]
Abstract
Since the work of Walter Schottky, it is known that the shot-noise power for a completely uncorrelated set of electrons increases linearly with the time-averaged current. At zero temperature and in the absence of inelastic scattering, the linearity relation between noise power and average current is quite robust, in many cases even for correlated electrons. Through high-bias shot-noise measurements on single Au atom point contacts, we find that the noise power in the high-bias regime shows highly nonlinear behavior even leading to a decrease in shot noise with voltage. We explain this nonlinearity using a model based on quantum interference of electron waves with varying path difference due to scattering from randomly distributed defect sites in the leads, which makes the transmission probability for these electrons both energy and voltage dependent.
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Affiliation(s)
| | - Jan van Ruitenbeek
- (J.v.R.) E-mail: . Telephone: +31 (0)71 527 3477. Fax: +31 (0)71
527 5404
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5
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Yin Y. On-demand electron source with tunable energy distribution. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:285301. [PMID: 29808830 DOI: 10.1088/1361-648x/aac843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
We propose a scheme to manipulate the electron-hole excitation in the voltage pulse electron source, which can be realized by a voltage-driven Ohmic contact connecting to a quantum hall edge channel. It has been known that the electron-hole excitation can be suppressed via Lorentzian pulses, leading to noiseless electron current. We show that, instead of the Lorentzian pulses, driven via the voltage pulse [Formula: see text] with duration t 0, the electron-hole excitation can be tuned so that the corresponding energy distribution of the emitted electrons follows the Fermi distribution with temperature [Formula: see text], with T S being the electron temperature in the Ohmic contact. Such Fermi distribution can be established without introducing additional energy relaxation mechanism and can be detected via shot noise thermometry technique, making it helpful in the study of thermal transport and decoherence in mesoscopic system.
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Affiliation(s)
- Y Yin
- Laboratory of Mesoscopic and Low Dimensional Physics, Department of Physics, Sichuan University, Chengdu, Sichuan 610064, People's Republic of China
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6
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Seo M, Roulleau P, Roche P, Glattli DC, Sanquer M, Jehl X, Hutin L, Barraud S, Parmentier FD. Strongly Correlated Charge Transport in Silicon Metal-Oxide-Semiconductor Field-Effect Transistor Quantum Dots. PHYSICAL REVIEW LETTERS 2018; 121:027701. [PMID: 30085716 DOI: 10.1103/physrevlett.121.027701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Indexed: 06/08/2023]
Abstract
Quantum shot noise probes the dynamics of charge transfers through a quantum conductor, reflecting whether quasiparticles flow across the conductor in a steady stream, or in syncopated bursts. We have performed high-sensitivity shot noise measurements in a quantum dot obtained in a silicon metal-oxide-semiconductor field-effect transistor. The quality of our device allows us to precisely associate the different transport regimes and their statistics with the internal state of the quantum dot. In particular, we report on large current fluctuations in the inelastic cotunneling regime, corresponding to different highly correlated, non-Markovian charge transfer processes. We have also observed unusually large current fluctuations at low energy in the elastic cotunneling regime, the origin of which remains to be fully investigated.
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Affiliation(s)
- M Seo
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex, France
| | - P Roulleau
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex, France
| | - P Roche
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex, France
| | - D C Glattli
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex, France
| | - M Sanquer
- Université Grenoble Alpes, CEA, INAC-PHELIQS, 38000 Grenoble, France
| | - X Jehl
- Université Grenoble Alpes, CEA, INAC-PHELIQS, 38000 Grenoble, France
| | - L Hutin
- CEA, LETI, Minatec Campus, 38000 Grenoble, France
| | - S Barraud
- CEA, LETI, Minatec Campus, 38000 Grenoble, France
| | - F D Parmentier
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette cedex, France
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7
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Matsuo M, Ohnuma Y, Kato T, Maekawa S. Spin Current Noise of the Spin Seebeck Effect and Spin Pumping. PHYSICAL REVIEW LETTERS 2018; 120:037201. [PMID: 29400496 DOI: 10.1103/physrevlett.120.037201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Indexed: 06/07/2023]
Abstract
We theoretically investigate the fluctuation of a pure spin current induced by the spin Seebeck effect and spin pumping in a normal-metal-(NM-)ferromagnet(FM) bilayer system. Starting with a simple ferromagnet-insulator-(FI-)NM interface model with both spin-conserving and non-spin-conserving processes, we derive general expressions of the spin current and the spin-current noise at the interface within second-order perturbation of the FI-NM coupling strength, and estimate them for a yttrium-iron-garnet-platinum interface. We show that the spin-current noise can be used to determine the effective spin carried by a magnon modified by the non-spin-conserving process at the interface. In addition, we show that it provides information on the effective spin of a magnon, heating at the interface under spin pumping, and spin Hall angle of the NM.
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Affiliation(s)
- M Matsuo
- Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
| | - Y Ohnuma
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
| | - T Kato
- Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan
| | - S Maekawa
- Advanced Science Research Center, Japan Atomic Energy Agency, Tokai 319-1195, Japan
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8
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Mintchev M, Santoni L, Sorba P. Quantum fluctuations of entropy production for fermionic systems in the Landauer-Büttiker state. Phys Rev E 2017; 96:052124. [PMID: 29347744 DOI: 10.1103/physreve.96.052124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Indexed: 11/07/2022]
Abstract
The quantum fluctuations of the entropy production for fermionic systems in the Landauer-Büttiker nonequilibrium steady state are investigated. The probability distribution, governing these fluctuations, is explicitly derived by means of quantum field theory methods and analyzed in the zero frequency limit. It turns out that microscopic processes with positive, vanishing and negative entropy production occur in the system with nonvanishing probability. In spite of this fact, we show that all odd moments (in particular, the mean value of the entropy production) of the above distribution are non-negative. This result extends the second principle of thermodynamics to the quantum fluctuations of the entropy production in the Landauer-Büttiker state. The effect of the time reversal is also discussed.
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Affiliation(s)
- Mihail Mintchev
- Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica dell'Università di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy
| | - Luca Santoni
- Institute for Theoretical Physics and Center for Extreme Matter and Emergent Phenomena, Utrecht University, Leuvenlaan 4, 3584 CE Utrecht, the Netherlands
| | - Paul Sorba
- LAPTh, Laboratoire d'Annecy-le-Vieux de Physique Théorique, CNRS, Université de Savoie, BP 110, 74941 Annecy-le-Vieux Cedex, France
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9
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Tewari S, Sabater C, Kumar M, Stahl S, Crama B, van Ruitenbeek JM. Fast and accurate shot noise measurements on atomic-size junctions in the MHz regime. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:093903. [PMID: 28964189 DOI: 10.1063/1.5003391] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 09/04/2017] [Indexed: 06/07/2023]
Abstract
Shot noise measurements on atomic and molecular junctions provide rich information about the quantum transport properties of the junctions and on the inelastic scattering events taking place in the process. Dissipation at the nanoscale, a problem of central interest in nano-electronics, can be studied in its most explicit and simplified form. Here, we describe a measurement technique that permits extending previous noise measurements to a much higher frequency range, and to much higher bias voltage range, while maintaining a high accuracy in noise and conductance. We also demonstrate the advantages of having access to the spectral information for diagnostics.
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Affiliation(s)
- Sumit Tewari
- Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, Postbus 9504, 2300 Leiden, The Netherlands
| | - Carlos Sabater
- Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, Postbus 9504, 2300 Leiden, The Netherlands
| | - Manohar Kumar
- Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, Postbus 9504, 2300 Leiden, The Netherlands
| | - Stefan Stahl
- Stahl Electronics, Hauptstrasse 15, 67582 Mettenhein, Germany
| | - Bert Crama
- Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, Postbus 9504, 2300 Leiden, The Netherlands
| | - Jan M van Ruitenbeek
- Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, Postbus 9504, 2300 Leiden, The Netherlands
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10
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Jabdaraghi RN, Golubev DS, Pekola JP, Peltonen JT. Noise of a superconducting magnetic flux sensor based on a proximity Josephson junction. Sci Rep 2017; 7:8011. [PMID: 28808333 PMCID: PMC5556101 DOI: 10.1038/s41598-017-08710-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 07/17/2017] [Indexed: 11/09/2022] Open
Abstract
We demonstrate simultaneous measurements of DC transport properties and flux noise of a hybrid superconducting magnetometer based on the proximity effect (superconducting quantum interference proximity transistor, SQUIPT). The noise is probed by a cryogenic amplifier operating in the frequency range of a few MHz. In our non-optimized device, we achieve minimum flux noise ~4 μΦ0/Hz1/2, set by the shot noise of the probe tunnel junction. The flux noise performance can be improved by further optimization of the SQUIPT parameters, primarily minimization of the proximity junction length and cross section. Furthermore, the experiment demonstrates that the setup can be used to investigate shot noise in other nonlinear devices with high impedance. This technique opens the opportunity to measure sensitive magnetometers including SQUIPT devices with very low dissipation.
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Affiliation(s)
- R N Jabdaraghi
- Low Temperature Laboratory, Department of Applied Physics, Aalto University School of Science, P.O. Box 13500, FI-00076, Aalto, Finland.
| | - D S Golubev
- Low Temperature Laboratory, Department of Applied Physics, Aalto University School of Science, P.O. Box 13500, FI-00076, Aalto, Finland
| | - J P Pekola
- Low Temperature Laboratory, Department of Applied Physics, Aalto University School of Science, P.O. Box 13500, FI-00076, Aalto, Finland
| | - J T Peltonen
- Low Temperature Laboratory, Department of Applied Physics, Aalto University School of Science, P.O. Box 13500, FI-00076, Aalto, Finland
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11
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Primary thermometry triad at 6 mK in mesoscopic circuits. Nat Commun 2016; 7:12908. [PMID: 27659941 PMCID: PMC5036159 DOI: 10.1038/ncomms12908] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 08/11/2016] [Indexed: 11/16/2022] Open
Abstract
Quantum physics emerge and develop as temperature is reduced. Although mesoscopic electrical circuits constitute an outstanding platform to explore quantum behaviour, the challenge in cooling the electrons impedes their potential. The strong coupling of such micrometre-scale devices with the measurement lines, combined with the weak coupling to the substrate, makes them extremely difficult to thermalize below 10 mK and imposes in situ thermometers. Here we demonstrate electronic quantum transport at 6 mK in micrometre-scale mesoscopic circuits. The thermometry methods are established by the comparison of three in situ primary thermometers, each involving a different underlying physics. The employed combination of quantum shot noise, quantum back action of a resistive circuit and conductance oscillations of a single-electron transistor covers a remarkably broad spectrum of mesoscopic phenomena. The experiment, performed in vacuum using a standard cryogen-free dilution refrigerator, paves the way towards the sub-millikelvin range with additional thermalization and refrigeration techniques. Mesoscopic electrical circuits are an ideal platform to explore quantum phenomena, but this requires cooling the electrons to very low temperature, which is challenging. Here, the authors employ three different in situ thermometers to report electronic quantum transport at 6mK in a micrometer-scale circuit.
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12
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Chen R, Natelson D. Evolution of shot noise in suspended lithographic gold break junctions with bias and temperature. NANOTECHNOLOGY 2016; 27:245201. [PMID: 27152886 DOI: 10.1088/0957-4484/27/24/245201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Shot noise is a powerful tool to probe correlations and microscopic transport details that conductance measurements alone cannot reveal. Even in atomic-scale Au devices that are well described by Landauer-Büttiker physics, complications remain such as local heating and electron-phonon interactions. We report systematic rf measurements of shot noise in individual atomic-scale gold break junctions at multiple temperatures, with most bias voltages well above the energy of the Au optical phonon mode. Motivated by the previous experimental evidence that electron-phonon interactions can modify Fano factors and result in kinked features in bias dependence of shot noise, we find that the temperature dependence of shot noise from 4.2 to 100 K is minimal. Enhanced Fano factors near [Formula: see text] and features beyond simply linear bias dependence of shot noise near the [Formula: see text] plateau are observed. Both are believed to have non-interacting origins and the latter likely results from slightly bias-dependent transmittance of the dominant quantum channel.
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Affiliation(s)
- Ruoyu Chen
- Department of Physics and Astronomy, Rice University, 6100 Main St., Houston, TX 77005, USA
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13
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Parmentier FD, Serkovic-Loli LN, Roulleau P, Glattli DC. Photon-Assisted Shot Noise in Graphene in the Terahertz Range. PHYSICAL REVIEW LETTERS 2016; 116:227401. [PMID: 27314736 DOI: 10.1103/physrevlett.116.227401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Indexed: 06/06/2023]
Abstract
When subjected to electromagnetic radiation, the fluctuation of the electronic current across a quantum conductor increases. This additional noise, called photon-assisted shot noise, arises from the generation and subsequent partition of electron-hole pairs in the conductor. The physics of photon-assisted shot noise has been thoroughly investigated at microwave frequencies up to 20 GHz, and its robustness suggests that it could be extended to the terahertz (THz) range. Here, we present measurements of the quantum shot noise generated in a graphene nanoribbon subjected to a THz radiation. Our results show signatures of photon-assisted shot noise, further demonstrating that hallmark time-dependant quantum transport phenomena can be transposed to the THz range.
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Affiliation(s)
- F D Parmentier
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette cedex, France
| | - L N Serkovic-Loli
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette cedex, France
| | - P Roulleau
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette cedex, France
| | - D C Glattli
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay 91191 Gif-sur-Yvette cedex, France
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14
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KOBAYASHI K. What can we learn from noise? - Mesoscopic nonequilibrium statistical physics. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2016; 92:204-221. [PMID: 27477456 PMCID: PMC5114290 DOI: 10.2183/pjab.92.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 05/30/2016] [Indexed: 06/06/2023]
Abstract
Mesoscopic systems - small electric circuits working in quantum regime - offer us a unique experimental stage to explorer quantum transport in a tunable and precise way. The purpose of this Review is to show how they can contribute to statistical physics. We introduce the significance of fluctuation, or equivalently noise, as noise measurement enables us to address the fundamental aspects of a physical system. The significance of the fluctuation theorem (FT) in statistical physics is noted. We explain what information can be deduced from the current noise measurement in mesoscopic systems. As an important application of the noise measurement to statistical physics, we describe our experimental work on the current and current noise in an electron interferometer, which is the first experimental test of FT in quantum regime. Our attempt will shed new light in the research field of mesoscopic quantum statistical physics.
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Affiliation(s)
- Kensuke KOBAYASHI
- Graduate School of Science, Osaka University, Toyonaka, Osaka, Japan
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15
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Matsuo S, Takeshita S, Tanaka T, Nakaharai S, Tsukagoshi K, Moriyama T, Ono T, Kobayashi K. Edge mixing dynamics in graphene p-n junctions in the quantum Hall regime. Nat Commun 2015; 6:8066. [PMID: 26337445 PMCID: PMC4569692 DOI: 10.1038/ncomms9066] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/13/2015] [Indexed: 11/09/2022] Open
Abstract
Massless Dirac electron systems such as graphene exhibit a distinct half-integer quantum Hall effect, and in the bipolar transport regime co-propagating edge states along the p–n junction are realized. Additionally, these edge states are uniformly mixed at the junction, which makes it a unique structure to partition electrons in these edge states. Although many experimental works have addressed this issue, the microscopic dynamics of electron partition in this peculiar structure remains unclear. Here we performed shot-noise measurements on the junction in the quantum Hall regime as well as at zero magnetic field. We found that, in sharp contrast with the zero-field case, the shot noise in the quantum Hall regime is finite in the bipolar regime, but is strongly suppressed in the unipolar regime. Our observation is consistent with the theoretical prediction and gives microscopic evidence that the edge states are uniquely mixed along the p–n junction. A graphene p–n junction can be created by connecting electrical gates that generate electron-doped and hole-doped areas in a flake. Here, the authors use shot-noise measurements to provide microscopic evidence that edge states are uniquely mixed along the junction in the quantum Hall regime.
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Affiliation(s)
- Sadashige Matsuo
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.,Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Shunpei Takeshita
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Takahiro Tanaka
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | | | | | - Takahiro Moriyama
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Teruo Ono
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Kensuke Kobayashi
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
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16
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Roche B, Roulleau P, Jullien T, Jompol Y, Farrer I, Ritchie DA, Glattli DC. Harvesting dissipated energy with a mesoscopic ratchet. Nat Commun 2015; 6:6738. [PMID: 25828578 DOI: 10.1038/ncomms7738] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 02/21/2015] [Indexed: 11/09/2022] Open
Abstract
The search for new efficient thermoelectric devices converting waste heat into electrical energy is of major importance. The physics of mesoscopic electronic transport offers the possibility to develop a new generation of nanoengines with high efficiency. Here we describe an all-electrical heat engine harvesting and converting dissipated power into an electrical current. Two capacitively coupled mesoscopic conductors realized in a two-dimensional conductor form the hot source and the cold converter of our device. In the former, controlled Joule heating generated by a voltage-biased quantum point contact results in thermal voltage fluctuations. By capacitive coupling the latter creates electric potential fluctuations in a cold chaotic cavity connected to external leads by two quantum point contacts. For unequal quantum point contact transmissions, a net electrical current is observed proportional to the heat produced.
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Affiliation(s)
- B Roche
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS UMR 3680), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - P Roulleau
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS UMR 3680), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - T Jullien
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS UMR 3680), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - Y Jompol
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS UMR 3680), CEA Saclay, F-91191 Gif-sur-Yvette, France
| | - I Farrer
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - D A Ritchie
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK
| | - D C Glattli
- Nanoelectronics Group, Service de Physique de l'Etat Condensé, IRAMIS/DSM (CNRS UMR 3680), CEA Saclay, F-91191 Gif-sur-Yvette, France
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17
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Hashisaka M, Ota T, Muraki K, Fujisawa T. Shot-noise evidence of fractional quasiparticle creation in a local fractional quantum Hall state. PHYSICAL REVIEW LETTERS 2015; 114:056802. [PMID: 25699462 DOI: 10.1103/physrevlett.114.056802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Indexed: 06/04/2023]
Abstract
We experimentally identify fractional quasiparticle creation in a tunneling process through a local fractional quantum Hall (FQH) state. The local FQH state is prepared in a low-density region near a quantum point contact in an integer quantum Hall (IQH) system. Shot-noise measurements reveal a clear transition from elementary-charge tunneling at low bias to fractional-charge tunneling at high bias. The fractional shot noise is proportional to T(1)(1-T(1)) over a wide range of T(1), where T(1) is the transmission probability of the IQH edge channel. This binomial distribution indicates that fractional quasiparticles emerge from the IQH state to be transmitted through the local FQH state. The study of this tunneling process enables us to elucidate the dynamics of Laughlin quasiparticles in FQH systems.
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Affiliation(s)
- Masayuki Hashisaka
- Department of Physics, Tokyo Institute of Technology, 2-12-1-H81 Ookayama, Meguro, Tokyo 152-8551, Japan
| | - Tomoaki Ota
- Department of Physics, Tokyo Institute of Technology, 2-12-1-H81 Ookayama, Meguro, Tokyo 152-8551, Japan
| | - Koji Muraki
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Toshimasa Fujisawa
- Department of Physics, Tokyo Institute of Technology, 2-12-1-H81 Ookayama, Meguro, Tokyo 152-8551, Japan
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18
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Detecting noise with shot noise using on-chip photon detector. Nat Commun 2015; 6:6130. [PMID: 25625934 DOI: 10.1038/ncomms7130] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 12/16/2014] [Indexed: 11/08/2022] Open
Abstract
The high-frequency radiation emitted by a quantum conductor presents a rising interest in quantum physics and condensed matter. However, its detection with microwave circuits is challenging. Here, we propose to use the photon-assisted shot noise for on-chip radiation detection. It is based on the low-frequency current noise generated by the partitioning of photon-excited electrons and holes, which are scattered inside the conductor. For a given electromagnetic coupling to the radiation, the photon-assisted shot noise response is shown to be independent on the nature and geometry of the quantum conductor used for the detection, up to a Fano factor, characterizing the type of scattering mechanism. Ordered in temperature or frequency range, from few tens of mK or GHz to several hundred of K or THz respectively, a wide variety of conductors can be used like Quantum Point Contacts (this work), diffusive metallic or semi-conducting films, graphene, carbon nanotubes and even molecule, opening new experimental opportunities in quantum physics.
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19
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Burtzlaff A, Weismann A, Brandbyge M, Berndt R. Shot noise as a probe of spin-polarized transport through single atoms. PHYSICAL REVIEW LETTERS 2015; 114:016602. [PMID: 25615489 DOI: 10.1103/physrevlett.114.016602] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Indexed: 06/04/2023]
Abstract
Single atoms on Au(111) surfaces have been contacted with the Au tip of a low temperature scanning tunneling microscope. The shot noise of the current through these contacts has been measured up to frequencies of 120 kHz and Fano factors have been determined to characterize the transport channels. The noise at Fe and Co atoms, the latter displaying a Kondo effect, indicates spin-polarized transport through a single channel. Transport calculations reproduce this observation.
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Affiliation(s)
- Andreas Burtzlaff
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany
| | - Alexander Weismann
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany
| | - Mads Brandbyge
- DTU Nanotech Department of Micro and Nanotechnology, NanoDTU, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark
| | - Richard Berndt
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany
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20
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Arakawa T, Shiogai J, Ciorga M, Utz M, Schuh D, Kohda M, Nitta J, Bougeard D, Weiss D, Ono T, Kobayashi K. Shot noise induced by nonequilibrium spin accumulation. PHYSICAL REVIEW LETTERS 2015; 114:016601. [PMID: 25615488 DOI: 10.1103/physrevlett.114.016601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Indexed: 06/04/2023]
Abstract
When an electric current passes across a potential barrier, the partition process of electrons at the barrier gives rise to the shot noise, reflecting the discrete nature of the electric charge. Here we report the observation of excess shot noise connected with a spin current which is induced by a nonequilibrium spin accumulation in an all-semiconductor lateral spin-valve device. We find that this excess shot noise is proportional to the spin current. Additionally, we determine quantitatively the spin-injection-induced electron temperature by measuring the current noise. Our experiments show that spin accumulation driven shot noise provides a novel means of investigating nonequilibrium spin transport.
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Affiliation(s)
- Tomonori Arakawa
- Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043 Osaka, Japan
| | - Junichi Shiogai
- Department of Materials Science, Tohoku University, 980-8579 Sendai, Miyagi, Japan
| | - Mariusz Ciorga
- Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - Martin Utz
- Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - Dieter Schuh
- Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - Makoto Kohda
- Department of Materials Science, Tohoku University, 980-8579 Sendai, Miyagi, Japan and PRESTO, Japan Science and Technology Agency, 332-0012 Kawaguchi, Saitama, Japan
| | - Junsaku Nitta
- Department of Materials Science, Tohoku University, 980-8579 Sendai, Miyagi, Japan
| | - Dominique Bougeard
- Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - Dieter Weiss
- Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany
| | - Teruo Ono
- Institute for Chemical Research, Kyoto University, 611-0011 Uji, Kyoto, Japan
| | - Kensuke Kobayashi
- Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043 Osaka, Japan
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21
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Hashisaka M, Ota T, Yamagishi M, Fujisawa T, Muraki K. Cross-correlation measurement of quantum shot noise using homemade transimpedance amplifiers. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:054704. [PMID: 24880392 DOI: 10.1063/1.4875588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report a cross-correlation measurement system, based on a new approach, which can be used to measure shot noise in a mesoscopic conductor at milliKelvin temperatures. In contrast to other measurement systems in which high-speed low-noise voltage amplifiers are commonly used, our system employs homemade transimpedance amplifiers (TAs). The low input impedance of the TAs significantly reduces the crosstalk caused by unavoidable parasitic capacitance between wires. The TAs are designed to have a flat gain over a frequency band from 2 kHz to 1 MHz. Low-noise performance is attained by installing the TAs at a 4 K stage of a dilution refrigerator. Our system thus fulfills the technical requirements for cross-correlation measurements: low noise floor, high frequency band, and negligible crosstalk between two signal lines. Using our system, shot noise generated at a quantum point contact embedded in a quantum Hall system is measured. The good agreement between the obtained shot-noise data and theoretical predictions demonstrates the accuracy of the measurements.
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Affiliation(s)
- Masayuki Hashisaka
- Department of Physics, Tokyo Institute of Technology, 2-12-1-H81 Ookayama, Meguro, Tokyo 152-8551, Japan
| | - Tomoaki Ota
- Department of Physics, Tokyo Institute of Technology, 2-12-1-H81 Ookayama, Meguro, Tokyo 152-8551, Japan
| | - Masakazu Yamagishi
- Department of Physics, Tokyo Institute of Technology, 2-12-1-H81 Ookayama, Meguro, Tokyo 152-8551, Japan
| | - Toshimasa Fujisawa
- Department of Physics, Tokyo Institute of Technology, 2-12-1-H81 Ookayama, Meguro, Tokyo 152-8551, Japan
| | - Koji Muraki
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
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22
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Edge JM, Li J, Delplace P, Büttiker M. Z2 peak of noise correlations in a quantum spin Hall insulator. PHYSICAL REVIEW LETTERS 2013; 110:246601. [PMID: 25165948 DOI: 10.1103/physrevlett.110.246601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Indexed: 06/03/2023]
Abstract
We investigate the current noise correlations at a quantum point contact in a quantum spin Hall structure, focusing on the effect of a weak magnetic field in the presence of disorder. For the case of two equally biased terminals we discover a robust peak: the noise correlations vanish at B = 0 and are negative for B ≠ 0. We find that the character of this peak is intimately related to the interplay between time reversal symmetry and the helical nature of the edge states and call it the Z2 peak.
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Affiliation(s)
- Jonathan M Edge
- Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands
| | - Jian Li
- Département de Physique Théorique, Université de Genève, CH-1211 Genève, Switzerland
| | - Pierre Delplace
- Département de Physique Théorique, Université de Genève, CH-1211 Genève, Switzerland
| | - Markus Büttiker
- Département de Physique Théorique, Université de Genève, CH-1211 Genève, Switzerland
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23
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Bocquillon E, Parmentier FD, Grenier C, Berroir JM, Degiovanni P, Glattli DC, Plaçais B, Cavanna A, Jin Y, Fève G. Electron quantum optics: partitioning electrons one by one. PHYSICAL REVIEW LETTERS 2012; 108:196803. [PMID: 23003072 DOI: 10.1103/physrevlett.108.196803] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Indexed: 06/01/2023]
Abstract
We have realized a quantum optics like Hanbury Brown-Twiss (HBT) experiment by partitioning, on an electronic beam splitter, single elementary electronic excitations produced one by one by an on-demand emitter. We show that the measurement of the output currents correlations in the HBT geometry provides a direct counting, at the single charge level, of the elementary excitations (electron-hole pairs) generated by the emitter at each cycle. We observe the antibunching of low energy excitations emitted by the source with thermal excitations of the Fermi sea already present in the input leads of the splitter, which suppresses their contribution to the partition noise. This effect is used to probe the energy distribution of the emitted wave packets.
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Affiliation(s)
- E Bocquillon
- Laboratoire Pierre Aigrain, Ecole Normale Supérieure, CNRS (UMR 8551), Université P. et M. Curie, 24 rue Lhomond, 75231 Paris Cedex 05, France
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24
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Kumar M, Avriller R, Yeyati AL, van Ruitenbeek JM. Detection of vibration-mode scattering in electronic shot noise. PHYSICAL REVIEW LETTERS 2012; 108:146602. [PMID: 22540815 DOI: 10.1103/physrevlett.108.146602] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Indexed: 05/31/2023]
Abstract
We present shot noise measurements on Au nanowires showing very pronounced vibration-mode features. In accordance to recent theoretical predictions the sign of the inelastic signal, i.e., the signal due to vibration excitations, depends on the transmission probability becoming negative below a certain transmission value. We argue that the negative contribution to noise arises from coherent two-electron processes mediated by electron-phonon scattering and the Pauli exclusion principle. These signals can provide unique information on the local phonon population and lattice temperature of the nanoscale system.
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Affiliation(s)
- Manohar Kumar
- Kamerlingh Onnes Laboratorium, Universiteit Leiden, PO Box 9504, 2300 RA Leiden, The Netherlands
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25
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Micolich AP. What lurks below the last plateau: experimental studies of the 0.7 × 2e(2)/h conductance anomaly in one-dimensional systems. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:443201. [PMID: 21997403 DOI: 10.1088/0953-8984/23/44/443201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The integer quantised conductance of one-dimensional electron systems is a well-understood effect of quantum confinement. A number of fractionally quantised plateaus are also commonly observed. They are attributed to many-body effects, but their precise origin is still a matter of debate, having attracted considerable interest over the past 15 years. This review reports on experimental studies of fractionally quantised plateaus in semiconductor quantum point contacts and quantum wires, focusing on the 0.7 × 2e(2)/h conductance anomaly, its analogues at higher conductances and the zero-bias peak observed in the dc source-drain bias for conductances less than 2e(2)/h.
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Affiliation(s)
- A P Micolich
- School of Physics, University of New South Wales, Sydney, NSW 2052, Australia.
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26
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Parmentier FD, Mahé A, Denis A, Berroir JM, Glattli DC, Plaçais B, Fève G. A high sensitivity ultralow temperature RF conductance and noise measurement setup. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:013904. [PMID: 21280842 DOI: 10.1063/1.3518945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report on the realization of a high sensitivity RF noise measurement scheme to study small current fluctuations of mesoscopic systems at milli-Kelvin temperatures. The setup relies on the combination of an interferometric amplification scheme and a quarter-wave impedance transformer, allowing the measurement of noise power spectral densities with gigahertz bandwidth up to five orders of magnitude below the amplifier noise floor. We simultaneously measure the high frequency conductance of the sample by derivating a portion of the signal to a microwave homodyne detection. We describe the principle of the setup, as well as its implementation and calibration. Finally, we show that our setup allows to fully characterize a subnanosecond on-demand single electron source. More generally, its sensitivity and bandwidth make it suitable for applications manipulating single charges at GHz frequencies.
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Affiliation(s)
- F D Parmentier
- Laboratoire Pierre Aigrain, Ecole Normale Supérieure, CNRS, UMR, Université P. et M. Curie, Université D. Diderot, Paris, France
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27
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Gutman DB, Gefen Y, Mirlin AD. Full counting statistics of a Luttinger liquid conductor. PHYSICAL REVIEW LETTERS 2010; 105:256802. [PMID: 21231608 DOI: 10.1103/physrevlett.105.256802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Indexed: 05/30/2023]
Abstract
Nonequilibrium bosonization technique is used to study current fluctuations of interacting electrons in a single-channel quantum wire representing a Luttinger liquid (LL) conductor. An exact expression for the time resolved full counting statistics of the transmitted charge is derived. It is given by the Fredholm determinant of the counting operator with a time-dependent scattering phase. The result has a form of counting statistics of noninteracting particles with fractional charges, induced by scattering off the boundaries between the LL wire and the noninteracting leads.
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Affiliation(s)
- D B Gutman
- Department of Physics, Bar Ilan University, Ramat Gan 52900, Israel
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28
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29
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Branschädel A, Boulat E, Saleur H, Schmitteckert P. Shot noise in the self-dual interacting resonant level model. PHYSICAL REVIEW LETTERS 2010; 105:146805. [PMID: 21230859 DOI: 10.1103/physrevlett.105.146805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Indexed: 05/30/2023]
Abstract
By using two independent and complementary approaches, we compute exactly the shot noise in an out-of-equilibrium interacting impurity model, the interacting resonant level model at its self-dual point. An analytical approach based on the thermodynamical Bethe ansatz allows us to obtain the density matrix in the presence of a bias voltage, which in turn allows for the computation of any observable. A time-dependent density matrix renormalization group technique that has proven to yield the correct result for a free model (the resonant level model) is shown to be in perfect agreement with the former method.
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Affiliation(s)
- A Branschädel
- Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology, 76021 Karlsruhe, Germany
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30
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Bednorz A, Belzig W. Quasiprobabilistic interpretation of weak measurements in mesoscopic junctions. PHYSICAL REVIEW LETTERS 2010; 105:106803. [PMID: 20867538 DOI: 10.1103/physrevlett.105.106803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Indexed: 05/29/2023]
Abstract
The impossibility of measuring noncommuting quantum mechanical observables is one of the most fascinating consequences of the quantum mechanical postulates. Hence, to date the investigation of quantum measurement and projection is a fundamentally interesting topic. We propose to test the concept of weak measurement of noncommuting observables in mesoscopic transport experiments, using a quasiprobabilistic description. We derive an inequality for current correlators, which is satisfied by every classical probability but violated by high-frequency fourth-order cumulants in the quantum regime for experimentally feasible parameters.
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Affiliation(s)
- Adam Bednorz
- Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany.
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31
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Schneider NL, Schull G, Berndt R. Optical probe of quantum shot-noise reduction at a single-atom contact. PHYSICAL REVIEW LETTERS 2010; 105:026601. [PMID: 20867722 DOI: 10.1103/physrevlett.105.026601] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Indexed: 05/13/2023]
Abstract
Visible and infrared light emitted at a Ag-Ag(111) junction has been investigated from tunneling to single-atom contact conditions with a scanning tunneling microscope. The light intensity varies in a highly nonlinear fashion with the conductance of the junction and exhibits a minimum at conductances close to the conductance quantum. The data are interpreted in terms of current noise at optical frequencies, which is characteristic of partially open transport channels.
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Affiliation(s)
- Natalia L Schneider
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, D-24098 Kiel, Germany
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32
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Wheeler PJ, Russom JN, Evans K, King NS, Natelson D. Shot noise suppression at room temperature in atomic-scale Au junctions. NANO LETTERS 2010; 10:1287-1292. [PMID: 20205414 DOI: 10.1021/nl904052r] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Shot noise encodes additional information not directly inferable from simple electronic transport measurements. Previous measurements in atomic-scale metal junctions at cryogenic temperatures have shown suppression of the shot noise at particular conductance values. This suppression demonstrates that transport in these structures proceeds via discrete quantum channels. Using a high-frequency technique, we simultaneously acquire noise data and conductance histograms in Au junctions at room temperature and ambient conditions. We observe noise suppression at up to three conductance quanta, with possible indications of current-induced local heating and 1/f noise in the contact region at high biases. These measurements demonstrate the quantum character of transport at room temperature at the atomic scale. This technique provides an additional tool for studying dissipation and correlations in nanodevices.
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Affiliation(s)
- P J Wheeler
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
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33
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Bid A, Ofek N, Heiblum M, Umansky V, Mahalu D. Shot noise and charge at the 2/3 composite fractional quantum Hall state. PHYSICAL REVIEW LETTERS 2009; 103:236802. [PMID: 20366163 DOI: 10.1103/physrevlett.103.236802] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Indexed: 05/29/2023]
Abstract
The exact structure of edge modes in "hole conjugate" fractional quantum Hall states remains an unsolved issue despite significant experimental and theoretical efforts devoted to their understanding. Recently, there has been a surge of interest in such studies led by the search for neutral modes, which in some cases may lead to exotic statistical properties of the excitations. In this Letter, we report on detailed measurements of shot noise, produced by partitioning of the more familiar 2/3 state. We find a fractional charge of (2/3)e at the lowest temperature, decreasing to e/3 at an elevated temperature. Surprisingly, strong shot noise had been measured on a clear 1/3 plateau upon partitioning the 2/3 state. This behavior suggests an uncommon picture of the composite edge channels quite different from the accepted one.
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Affiliation(s)
- Aveek Bid
- Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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34
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Bednorz A, Belzig W. Formulation of time-resolved counting statistics based on a positive-operator-valued measure. PHYSICAL REVIEW LETTERS 2008; 101:206803. [PMID: 19113367 DOI: 10.1103/physrevlett.101.206803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Indexed: 05/27/2023]
Abstract
We propose a derivation of the full counting statistics of electronic current based on a positive-operator-valued measure. Our approach justifies the Levitov-Lesovik formula in the long-time limit, but can be generalized to the detection of finite-frequency noise correlations. The combined action of the projection postulate and the quantum formula for current noise at high frequencies imply an additional white noise. Estimates for this additional noise are in accordance with known experiments. We propose an experimental test of our conjecture by a simultaneous measurement of high- and low-frequency noise.
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Affiliation(s)
- Adam Bednorz
- Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany and University of Warsaw, Hoza 69, PL-00681 Warsaw, Poland.
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35
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Kornyshev AA, Kuznetsov AM. Simple theory of current fluctuations and noise in bridge-mediated nano-junctions. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2008; 20:374103. [PMID: 21694411 DOI: 10.1088/0953-8984/20/37/374103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We develop a simplified, model theory of noise caused by highly damped oscillating conformational fluctuations of a chain molecule mediating a nano-junction. Considering the most 'primitive' approximation of direct tunneling of electrons and barrier coupling with collective coordinates that describe internal conformations of the chain molecule, we derive approximate analytical formulas for the temporary current correlation function, noise power, and Fano factor. We analyze the role of different cumulative parameters of the model that affect the noise, as well as the effect of the temperature and of the number of groups in the chain. We present this analysis in expectation of experiments on this type of noise and in an attempt to trigger such experiments.
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Affiliation(s)
- A A Kornyshev
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
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36
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Altimiras C, Gennser U, Cavanna A, Mailly D, Pierre F. Experimental test of the dynamical coulomb blockade theory for short coherent conductors. PHYSICAL REVIEW LETTERS 2007; 99:256805. [PMID: 18233546 DOI: 10.1103/physrevlett.99.256805] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Indexed: 05/25/2023]
Abstract
We observed the recently predicted quantum suppression of dynamical Coulomb blockade on short coherent conductors by measuring the conductance of a quantum point contact embedded in a tunable on-chip circuit. Taking advantage of the circuit modularity we measured most parameters used by the theory. This allowed us to perform a reliable and quantitative experimental test of the theory. Dynamical Coulomb blockade corrections, probed up to the second conductance plateau of the quantum point contact, are found to be accurately normalized by the same Fano factor as quantum shot noise, in excellent agreement with the theoretical predictions.
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Affiliation(s)
- C Altimiras
- Phynano Team, Laboratoire de Photonique et de Nanostructures (LPN)-CNRS, Route de Nozay, 91460 Marcoussis, France
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37
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Zakka-Bajjani E, Ségala J, Portier F, Roche P, Glattli DC, Cavanna A, Jin Y. Experimental test of the high-frequency quantum shot noise theory in a quantum point contact. PHYSICAL REVIEW LETTERS 2007; 99:236803. [PMID: 18233393 DOI: 10.1103/physrevlett.99.236803] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Indexed: 05/25/2023]
Abstract
We report on direct measurements of the electronic shot noise of a quantum point contact at frequencies nu in the range 4-8 GHz. The very small energy scale used ensures energy independent transmissions of the few transmitted electronic modes and their accurate knowledge. Both the thermal energy and the quantum point contact drain-source voltage V_{ds} are comparable to the photon energy hnu leading to observation of the shot noise suppression when V_{ds}<hnu/e. Our measurements provide the first complete test of the finite frequency shot noise scattering theory without adjustable parameters.
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Affiliation(s)
- E Zakka-Bajjani
- Nanoelectronic Group, Service de Physique de l'Etat Condensé, CEA Saclay, F-91191 Gif-Sur-Yvette, France
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Herrmann LG, Delattre T, Morfin P, Berroir JM, Plaçais B, Glattli DC, Kontos T. Shot noise in Fabry-Perot interferometers based on carbon nanotubes. PHYSICAL REVIEW LETTERS 2007; 99:156804. [PMID: 17995203 DOI: 10.1103/physrevlett.99.156804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 08/07/2007] [Indexed: 05/25/2023]
Abstract
We report on shot noise measurements in carbon nanotube based Fabry-Perot electronic interferometers. As a consequence of quantum interference, the noise power spectral density oscillates as a function of the voltage applied to the gate electrode. The quantum shot noise theory accounts for the data quantitatively and allows us to determine directly the transmissions of the two channels characterizing the nanotube. In the weak backscattering regime, the dependence of the noise on the backscattering current is found weaker than expected, pointing either to electron-electron interactions or to weak decoherence.
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Affiliation(s)
- L G Herrmann
- Laboratoire Pierre Aigrain, CNRS UMR 8551, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
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39
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Neder I, Ofek N, Chung Y, Heiblum M, Mahalu D, Umansky V. Interference between two indistinguishable electrons from independent sources. Nature 2007; 448:333-7. [PMID: 17637665 DOI: 10.1038/nature05955] [Citation(s) in RCA: 255] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Accepted: 05/22/2007] [Indexed: 11/08/2022]
Abstract
Very much like the ubiquitous quantum interference of a single particle with itself, quantum interference of two independent, but indistinguishable, particles is also possible. For a single particle, the interference is between the amplitudes of the particle's wavefunctions, whereas the interference between two particles is a direct result of quantum exchange statistics. Such interference is observed only in the joint probability of finding the particles in two separated detectors, after they were injected from two spatially separated and independent sources. Experimental realizations of two-particle interferometers have been proposed; in these proposals it was shown that such correlations are a direct signature of quantum entanglement between the spatial degrees of freedom of the two particles ('orbital entanglement'), even though they do not interact with each other. In optics, experiments using indistinguishable pairs of photons encountered difficulties in generating pairs of independent photons and synchronizing their arrival times; thus they have concentrated on detecting bunching of photons (bosons) by coincidence measurements. Similar experiments with electrons are rather scarce. Cross-correlation measurements between partitioned currents, emanating from one source, yielded similar information to that obtained from auto-correlation (shot noise) measurements. The proposal of ref. 3 is an electronic analogue to the historical Hanbury Brown and Twiss experiment with classical light. It is based on the electronic Mach-Zehnder interferometer that uses edge channels in the quantum Hall effect regime. Here we implement such an interferometer. We partitioned two independent and mutually incoherent electron beams into two trajectories, so that the combined four trajectories enclosed an Aharonov-Bohm flux. Although individual currents and their fluctuations (shot noise measured by auto-correlation) were found to be independent of the Aharonov-Bohm flux, the cross-correlation between current fluctuations at two opposite points across the device exhibited strong Aharonov-Bohm oscillations, suggesting orbital entanglement between the two electron beams.
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Affiliation(s)
- I Neder
- Braun Center for Submicron Research, Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel
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40
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DiCarlo L, Zhang Y, McClure DT, Reilly DJ, Marcus CM, Pfeiffer LN, West KW. Shot-noise signatures of 0.7 structure and spin in a quantum point contact. PHYSICAL REVIEW LETTERS 2006; 97:036810. [PMID: 16907535 DOI: 10.1103/physrevlett.97.036810] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2006] [Indexed: 05/11/2023]
Abstract
We report simultaneous measurement of shot noise and dc transport in a quantum point contact as a function of source-drain bias, gate voltage, and in-plane magnetic field. Shot noise at zero field exhibits an asymmetry related to the 0.7 structure in conductance. The asymmetry in noise evolves smoothly into the symmetric signature of spin-resolved electron transmission at high field. Comparison to a phenomenological model with density-dependent level splitting yields good quantitative agreement.
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Affiliation(s)
- L DiCarlo
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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41
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Onac E, Balestro F, van Beveren LHW, Hartmann U, Nazarov YV, Kouwenhoven LP. Using a quantum dot as a high-frequency shot noise detector. PHYSICAL REVIEW LETTERS 2006; 96:176601. [PMID: 16712318 DOI: 10.1103/physrevlett.96.176601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Indexed: 05/09/2023]
Abstract
We present the experimental realization of a quantum dot (QD) operating as a high-frequency noise detector. Current fluctuations produced in a nearby quantum point contact (QPC) ionize the QD and induce transport through excited states. The resulting transient current through the QD represents our detector signal. We investigate its dependence on the QPC transmission and voltage bias. We observe and explain a quantum threshold feature and a saturation in the detector signal. This experimental and theoretical study is relevant in understanding the backaction of a QPC used as a charge detector.
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Affiliation(s)
- E Onac
- Kavli Institute of Nanoscience Delft, Delft University of Technology, The Netherlands.
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42
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Abstract
We report measurements of shot noise in the current through a single D2 molecule. The molecular junctions were formed by means of the mechanically controllable break junction technique. The configuration of the D2 molecule bridging the gap between two Pt tips is verified by use of point contact spectroscopy. Maintaining the same junction shot noise measurements were performed and the observed quantum suppression shows that conductance is carried dominantly by a single, almost fully transparent conductance channel. This observation allows us to decide between conflicting model calculations for this system, and this may serve as a benchmark for further computations on molecular junctions.
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Affiliation(s)
- D Djukic
- Kamerlingh Onnes Laboratorium, Universiteit Leiden, Postbus 9504, NL-2300 RA Leiden, The Netherlands
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43
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Oberholzer S, Bieri E, Schönenberger C, Giovannini M, Faist J. Positive cross correlations in a normal-conducting fermionic beam splitter. PHYSICAL REVIEW LETTERS 2006; 96:046804. [PMID: 16486869 DOI: 10.1103/physrevlett.96.046804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2005] [Indexed: 05/06/2023]
Abstract
We investigate a beam-splitter experiment implemented in a normal-conducting fermionic electron gas in the quantum Hall regime. The cross correlations between the current fluctuations in the two exit leads of the three terminal device are found to be negative, zero, or even positive, depending on the scattering mechanism within the device. Reversal of the cross correlation sign occurs due to interaction between different edge states and does not reflect the statistics of the fermionic particles which "antibunch."
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Affiliation(s)
- S Oberholzer
- Institut für Physik, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland.
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44
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Jordan AN, Büttiker M. Continuous quantum measurement with independent detector cross correlations. PHYSICAL REVIEW LETTERS 2005; 95:220401. [PMID: 16384197 DOI: 10.1103/physrevlett.95.220401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Indexed: 05/05/2023]
Abstract
We investigate the advantages of using two independent, linear detectors for continuous quantum measurement. For single-shot measurement, the detection process may be quantum limited if the detectors are twins. For weak continuous measurement, cross correlations allow a violation of the Korotkov-Averin bound for the detector's signal-to-noise ratio. The joint weak measurement of noncommuting observables is also investigated, and we find the cross correlation changes sign as a function of frequency, reflecting a crossover from incoherent relaxation to coherent, out of phase oscillations. Our results are applied to a double quantum-dot charge qubit, simultaneously measured by two quantum point contacts.
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Affiliation(s)
- Andrew N Jordan
- Département de Physique Théorique, Université de Genève, CH-1211 Genève 4, Switzerland
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45
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Bomze Y, Gershon G, Shovkun D, Levitov LS, Reznikov M. Measurement of counting statistics of electron transport in a tunnel junction. PHYSICAL REVIEW LETTERS 2005; 95:176601. [PMID: 16383849 DOI: 10.1103/physrevlett.95.176601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2005] [Indexed: 05/05/2023]
Abstract
We present measurements of the time-dependent fluctuations of electrical current in a voltage-biased tunnel junction. We were able to simultaneously extract the first three moments of the current counting statistics. Detailed comparison of the second and the third moments reveals that the statistics is accurately described as Poissonian, expected for spontaneous current fluctuations due to electron charge discreteness, realized in tunneling transport at negligible coupling to environment.
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Affiliation(s)
- Yu Bomze
- Department of Physics and Solid State Institute, Technion-IIT, Haifa 32000, Israel
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46
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Course 5 Noise in mesoscopic physics. NANOPHYSICS: COHERENCE AND TRANSPORT, ÉCOLE D'ÉTÉ DE PHYSIQUE DES HOUCHES SESSION LXXXI 2005. [DOI: 10.1016/s0924-8099(05)80047-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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47
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Roche P, Ségala J, Glattli DC, Nicholls JT, Pepper M, Graham AC, Thomas KJ, Simmons MY, Ritchie DA. Fano factor reduction on the 0.7 conductance structure of a ballistic one-dimensional wire. PHYSICAL REVIEW LETTERS 2004; 93:116602. [PMID: 15447363 DOI: 10.1103/physrevlett.93.116602] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2004] [Indexed: 05/24/2023]
Abstract
We have measured the nonequilibrium current noise in a ballistic one-dimensional wire which exhibits an additional conductance plateau at 0.7x2e(2)/h. The Fano factor shows a clear reduction on the 0.7 structure, and eventually vanishes upon applying a strong parallel magnetic field. These results provide experimental evidence that the 0.7 structure is associated with two conduction channels that have different transmission probabilities.
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Affiliation(s)
- P Roche
- Nanoelectronic group, Service de Physique de l'Etat Condensé, CEA Saclay, F-91191 Gif-sur-Yvette, France
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48
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Gabelli J, Reydellet LH, Fève G, Berroir JM, Plaçais B, Roche P, Glattli DC. Hanbury Brown-Twiss correlations to probe the population statistics of GHz photons emitted by conductors. PHYSICAL REVIEW LETTERS 2004; 93:056801. [PMID: 15323720 DOI: 10.1103/physrevlett.93.056801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2004] [Indexed: 05/24/2023]
Abstract
We present the first study of the statistics of GHz photons in quantum circuits, using Hanbury Brown and Twiss correlations. The super-Poissonian and Poissonian photon statistics of thermal and coherent sources, respectively, made of a resistor and a radio frequency generator, are measured down to the quantum regime at milli-Kelvin temperatures. As photon correlations are linked to the second and fourth moments of current fluctuations, this experiment, which is based on current cryogenic electronics, may become a standard for probing electron/photon statistics in quantum conductors.
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Affiliation(s)
- J Gabelli
- Laboratoire Pierre Aigrain, Département de Physique de l'Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
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49
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Green F, Thakur JS, Das MP. Where is the shot noise of a quantum point contact? PHYSICAL REVIEW LETTERS 2004; 92:156804. [PMID: 15169306 DOI: 10.1103/physrevlett.92.156804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2003] [Indexed: 05/24/2023]
Abstract
Reznikov et al. [Phys. Rev. Lett. 75, 3340 (1995)]] have presented definitive observations of nonequilibrium noise in a quantum point contact. Especially puzzling is the "anomalous" peak structure of the excess noise measured at constant current; to date it remains unexplained. We show that their experiment directly reveals the deep link between conservation principles in the electron gas and its low-dimensional, mesoscopic behavior. The keys to that connection are gauge invariance and the compressibility sum rule. These are central not only to the experiment of Reznikov et al., but to the very nature of all mesoscopic transport.
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Affiliation(s)
- Frederick Green
- Department of Theoretical Physics, Institute of Advanced Studies, The Australian National University, Canberra, ACT 0200, Australia
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50
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Samuelsson P, Sukhorukov EV, Büttiker M. Two-particle Aharonov-Bohm effect and entanglement in the electronic Hanbury Brown-Twiss setup. PHYSICAL REVIEW LETTERS 2004; 92:026805. [PMID: 14753955 DOI: 10.1103/physrevlett.92.026805] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2003] [Indexed: 05/24/2023]
Abstract
We analyze a Hanbury Brown-Twiss geometry in which particles are injected from two independent sources into a mesoscopic conductor in the quantum Hall regime. All partial waves end in different reservoirs without generating any single-particle interference; in particular, there is no single-particle Aharonov-Bohm effect. However, exchange effects lead to two-particle Aharonov-Bohm oscillations in the zero-frequency current cross correlations. We demonstrate that this is related to two-particle orbital entanglement, detected via violation of a Bell inequality. The transport is along edge states and only adiabatic quantum point contacts and normal reservoirs are employed.
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Affiliation(s)
- P Samuelsson
- Département de Physique Théorique, Université de Genève, CH-1211 Genève 4, Switzerland
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