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Popoff A, Rech J, Jonckheere T, Raymond L, Grémaud B, Malherbe S, Martin T. Scattering theory of non-equilibrium noise and delta Tcurrent fluctuations through a quantum dot. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:185301. [PMID: 35120336 DOI: 10.1088/1361-648x/ac5200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 02/04/2022] [Indexed: 06/14/2023]
Abstract
We consider the non-equilibrium zero frequency noise generated by a temperature gradient applied on a device composed of two normal leads separated by a quantum dot. We recall the derivation of the scattering theory for non-equilibrium noise for a general situation where both a bias voltage and a temperature gradient can coexist and put it in a historical perspective. We provide a microscopic derivation of zero frequency noise through a quantum dot based on a tight binding Hamiltonian, which constitutes a generalization of the seminal result obtained for the current in the context of the Keldysh formalism. For a single level quantum dot, the obtained transmission coefficient entering the scattering formula for the non-equilibrium noise corresponds to a Breit-Wigner resonance. We compute the delta-Tnoise as a function of the dot level position, and for a broad range of values of the dot level width, in the Breit-Wigner case, for two relevant situations which were considered recently in two separate experiments. In the regime where the two reservoir temperatures are comparable, our gradient expansion shows that the delta-Tnoise is dominated by its quadratic contribution, and is minimal close to resonance. In the opposite regime where one reservoir is much colder, the gradient expansion fails and we find the noise to be typically linear in temperature before saturating. In both situations, we conclude with a short discussion of the case where both a voltage bias and a temperature gradient are present, in order to address the potential competition with thermoelectric effects.
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Affiliation(s)
- A Popoff
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, IPhU, AMUtech, Marseille, France
- Collège Tinomana Ebb de Teva I Uta, BP 15001 - 98726 Mataiea, Tahiti, French Polynesia
| | - J Rech
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, IPhU, AMUtech, Marseille, France
| | - T Jonckheere
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, IPhU, AMUtech, Marseille, France
| | - L Raymond
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, IPhU, AMUtech, Marseille, France
| | - B Grémaud
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, IPhU, AMUtech, Marseille, France
| | - S Malherbe
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, IPhU, AMUtech, Marseille, France
- Département de Physique, Ecole Normale Supérieure, 45 Rue d'Ulm, 75005 Paris, France
| | - T Martin
- Aix Marseille Univ, Université de Toulon, CNRS, CPT, IPhU, AMUtech, Marseille, France
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2
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You C, Hong M, Bhusal N, Chen J, Quiroz-Juárez MA, Fabre J, Mostafavi F, Guo J, De Leon I, León-Montiel RDJ, Magaña-Loaiza OS. Observation of the modification of quantum statistics of plasmonic systems. Nat Commun 2021; 12:5161. [PMID: 34453050 PMCID: PMC8397772 DOI: 10.1038/s41467-021-25489-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 08/13/2021] [Indexed: 11/09/2022] Open
Abstract
For almost two decades, researchers have observed the preservation of the quantum statistical properties of bosons in a large variety of plasmonic systems. In addition, the possibility of preserving nonclassical correlations in light-matter interactions mediated by scattering among photons and plasmons stimulated the idea of the conservation of quantum statistics in plasmonic systems. It has also been assumed that similar dynamics underlie the conservation of the quantum fluctuations that define the nature of light sources. So far, plasmonic experiments have been performed in nanoscale systems in which complex multiparticle interactions are restrained. Here, we demonstrate that the quantum statistics of multiparticle systems are not always preserved in plasmonic platforms and report the observation of their modification. Moreover, we show that optical near fields provide additional scattering paths that can induce complex multiparticle interactions. Remarkably, the resulting multiparticle dynamics can, in turn, lead to the modification of the excitation mode of plasmonic systems. These observations are validated through the quantum theory of optical coherence for single- and multi-mode plasmonic systems. Our findings unveil the possibility of using multiparticle scattering to perform exquisite control of quantum plasmonic systems.
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Affiliation(s)
- Chenglong You
- Quantum Photonics Laboratory, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
| | - Mingyuan Hong
- Quantum Photonics Laboratory, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
| | - Narayan Bhusal
- Quantum Photonics Laboratory, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
| | - Jinnan Chen
- Department of Electrical and Computer Engineering, University of Alabama in Huntsville, Huntsville, AL, USA
| | - Mario A Quiroz-Juárez
- Departamento de Física, Universidad Autónoma Metropolitana Unidad Iztapalapa, Ciudad México, Mexico
| | - Joshua Fabre
- Quantum Photonics Laboratory, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
| | - Fatemeh Mostafavi
- Quantum Photonics Laboratory, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA
| | - Junpeng Guo
- Department of Electrical and Computer Engineering, University of Alabama in Huntsville, Huntsville, AL, USA
| | - Israel De Leon
- School of Engineering and Sciences, Tecnologico de Monterrey, Monterrey, Nuevo Leon, Mexico
| | | | - Omar S Magaña-Loaiza
- Quantum Photonics Laboratory, Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, USA.
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3
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Moskalets M. Auto- versus Cross-Correlation Noise in Periodically Driven Quantum Coherent Conductors. ENTROPY 2021; 23:e23040393. [PMID: 33806199 PMCID: PMC8066600 DOI: 10.3390/e23040393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/21/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022]
Abstract
Expressing currents and their fluctuations at the terminals of a multi-probe conductor in terms of the wave functions of carriers injected into the Fermi sea provides new insight into the physics of electric currents. This approach helps us to identify two physically different contributions to shot noise. In the quantum coherent regime, when current is carried by non-overlapping wave packets, the product of current fluctuations in different leads, the cross-correlation noise, is determined solely by the duration of the wave packet. In contrast, the square of the current fluctuations in one lead, the autocorrelation noise, is additionally determined by the coherence of the wave packet, which is associated with the spread of the wave packet in energy. The two contributions can be addressed separately in the weak back-scattering regime, when the autocorrelation noise depends only on the coherence. Analysis of shot noise in terms of these contributions allows us, in particular, to predict that no individual traveling particles with a real wave function, such as Majorana fermions, can be created in the Fermi sea in a clean manner, that is, without accompanying electron-hole pairs.
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Affiliation(s)
- Michael Moskalets
- Department of Metal and Semiconductor Physics, NTU "Kharkiv Polytechnic Institute", 61002 Kharkiv, Ukraine
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4
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Chandramouli RS, Srivastav RK, Kumar S. Electronic transport in chaotic mesoscopic cavities: A Kwant and random matrix theory based exploration. CHAOS (WOODBURY, N.Y.) 2020; 30:123120. [PMID: 33380063 DOI: 10.1063/5.0026039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/20/2020] [Indexed: 06/12/2023]
Abstract
We investigate the spectral fluctuations and electronic transport properties of chaotic mesoscopic cavities using Kwant, an open source Python programming language based package. Discretized chaotic billiard systems are used to model these mesoscopic cavities. For the spectral fluctuations, we study the ratio of consecutive eigenvalue spacings, and for the transport properties, we focus on Landauer conductance and shot noise power. We generate an ensemble of scattering matrices in Kwant, with desired number of open channels in the leads attached to the cavity. The results obtained from Kwant simulations, performed without or with magnetic field, are compared with the corresponding random matrix theory predictions for orthogonally and unitarily invariant ensembles. These two cases apply to the scenarios of preserved and broken time-reversal symmetry, respectively. In addition, we explore the orthogonal to unitary crossover statistics by varying the magnetic field and examine its relationship with the random matrix transition parameter.
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Affiliation(s)
| | - Rohit Kumar Srivastav
- Department of Physics, Shiv Nadar University, Gautam Buddha Nagar, Uttar Pradesh 201314, India
| | - Santosh Kumar
- Department of Physics, Shiv Nadar University, Gautam Buddha Nagar, Uttar Pradesh 201314, India
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5
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Esin I, Romito A, Gefen Y. Detection of Quantum Interference without an Interference Pattern. PHYSICAL REVIEW LETTERS 2020; 125:020405. [PMID: 32701343 DOI: 10.1103/physrevlett.125.020405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/21/2020] [Indexed: 06/11/2023]
Abstract
Quantum interference is typically detected through the dependence of the interference signal on certain parameters (path length, Aharonov-Bohm flux, etc.), which can be varied in a controlled manner. The destruction of interference by a which-path measurement is a paradigmatic manifestation of quantum effects. Here we report on a novel measurement protocol that realizes two objectives: (i) certifying that a measured signal is the result of interference avoiding the need to vary parameters of the underlying interferometer, and (ii) certifying that the interference signal at hand is of quantum nature. In particular, it yields a null outcome in the case of classical interference. Our protocol comprises measurements of cross-correlations between the readings of which-path weakly coupled detectors positioned at the respective interferometer's arms and the current in one of the interferometer's drains. We discuss its implementation with an experimentally available platform: an electronic Mach-Zehnder interferometer (MZI) coupled electrostatically to "detectors" (quantum point contacts).
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Affiliation(s)
- Iliya Esin
- Physics Department, Technion, 3200003 Haifa, Israel
| | - Alessandro Romito
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Yuval Gefen
- Department of Condensed Matter Physics, The Weizmann Institute of Science, Rehovot 76100, Israel
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Bragato M, Achilli S, Cargnoni F, Ceresoli D, Martinazzo R, Soave R, Trioni MI. Magnetic Moments and Electron Transport through Chromium-Based Antiferromagnetic Nanojunctions. MATERIALS (BASEL, SWITZERLAND) 2018; 11:E2030. [PMID: 30340431 PMCID: PMC6213584 DOI: 10.3390/ma11102030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 09/20/2018] [Accepted: 10/17/2018] [Indexed: 11/16/2022]
Abstract
We report the electronic, magnetic and transport properties of a prototypical antiferromagnetic (AFM) spintronic device. We chose Cr as the active layer because it is the only room-temperature AFM elemental metal. We sandwiched Cr between two non-magnetic metals (Pt or Au) with large spin-orbit coupling. We also inserted a buffer layer of insulating MgO to mimic the structure and finite resistivity of a real device. We found that, while spin-orbit has a negligible effect on the current flowing through the device, the MgO layer plays a crucial role. Its effect is to decouple the Cr magnetic moment from Pt (or Au) and to develop an overall spin magnetization. We have also calculated the spin-polarized ballistic conductance of the device within the Büttiker⁻Landauer framework, and we have found that for small applied bias our Pt/Cr/MgO/Pt device presents a spin polarization of the current amounting to ≃25%.
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Affiliation(s)
- Marco Bragato
- Department of Chemistry, University of Milan, 20133 Milan, Italy.
| | - Simona Achilli
- Department of Physics, University of Milan, 20133 Milan, Italy.
| | - Fausto Cargnoni
- Consiglio Nazionale delle Ricerche, Istituto di Scienze e Tecnologie Molecolari and INSTM UdR di Milano, via Golgi 19, 20133 Milan, Italy.
| | - Davide Ceresoli
- Consiglio Nazionale delle Ricerche, Istituto di Scienze e Tecnologie Molecolari and INSTM UdR di Milano, via Golgi 19, 20133 Milan, Italy.
| | - Rocco Martinazzo
- Department of Chemistry, University of Milan, 20133 Milan, Italy.
| | - Raffaella Soave
- Consiglio Nazionale delle Ricerche, Istituto di Scienze e Tecnologie Molecolari and INSTM UdR di Milano, via Golgi 19, 20133 Milan, Italy.
| | - Mario Italo Trioni
- Consiglio Nazionale delle Ricerche, Istituto di Scienze e Tecnologie Molecolari and INSTM UdR di Milano, via Golgi 19, 20133 Milan, Italy.
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7
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Jiang L, Feng L, Yao H, Zheng Y. Electronic transport property in Weyl semimetal with local Weyl cone tilt. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:115001. [PMID: 29419521 DOI: 10.1088/1361-648x/aaade4] [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
In realistic materials of Weyl semimetal (WSM), the Weyl cone tilt (WCT) is allowed due to the absence of Lorentz invariance in condensed matter physics. In this context, we theoretically study the electronic transport property in WSM with the local WCT as the scattering mechanism. In so doing, we establish an electronic transport structure of WSM with the WCT occurring only in the central region sandwiched between two pieces of semi-infinite WSM without the WCT. By means of two complementary theoretical approaches, i.e. the continuum-model method and the lattice-model method, the electronic transmission probability, the conductivity and the Fano factor as functions of the incident electron energy are calculated respectively. We find that the WCT can give rise to nontrivial intervalley scattering, as a result, the Klein tunneling is notably suppressed. More importantly, the minimal conductivity of a WSM shifts in energy from the Weyl nodal point. The Fano factor of the shot noise deviates obviously from the sub-Poissonian value in a two dimensional WSM with the WCT.
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Affiliation(s)
- Liwei Jiang
- Key Laboratory of Physics and Technology for Advanced Batteries(Ministry of Education), College of Physics, Jilin University, Changchun 130012, People's Republic of China
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8
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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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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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Agranov T, Meerson B. Fluctuations of absorption of interacting diffusing particles by multiple absorbers. Phys Rev E 2017; 95:062124. [PMID: 28709351 DOI: 10.1103/physreve.95.062124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Indexed: 11/07/2022]
Abstract
We study fluctuations of particle absorption by a three-dimensional domain with multiple absorbing patches. The domain is in contact with a gas of interacting diffusing particles. This problem is motivated by living cell sensing via multiple receptors distributed over the cell surface. Employing the macroscopic fluctuation theory, we calculate the covariance matrix of the particle absorption by different patches, extending previous works which addressed fluctuations of a single current. We find a condition when the sign of correlations between different patches is fully determined by the transport coefficients of the gas and is independent of the problem's geometry. We show that the fluctuating particle flux field typically develops vorticity. We establish a simple connection between the statistics of particle absorption by all the patches combined and the statistics of current in a nonequilibrium steady state in one dimension. We also discuss connections between the absorption statistics and (i) statistics of electric currents in multiterminal diffusive conductors and (ii) statistics of wave transmission through disordered media with multiple absorbers.
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Affiliation(s)
- Tal Agranov
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Baruch Meerson
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
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11
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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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12
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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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13
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Marian D, Colomés E, Oriols X. Time-dependent exchange and tunneling: detection at the same place of two electrons emitted simultaneously from different sources. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:245302. [PMID: 26030519 DOI: 10.1088/0953-8984/27/24/245302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two-particle scattering probabilities in tunneling scenarios with exchange interaction are analyzed with quasi-particle wave packets. Two initial one-particle wave packets (with opposite central momentums) are spatially localized at each side of a barrier. After impinging upon a tunneling barrier, each wave packet splits into transmitted and reflected components. When the initial two-particle anti-symmetrical state is defined as a Slater determinant of any type of (normalizable) one-particle wave packet, it is shown that the probability of detecting two (identically injected) electrons at the same side of the barrier is different from zero in very common (single or double barrier) scenarios. In some particular scenarios, the transmitted and reflected components become orthogonal and the mentioned probabilities reproduce those values associated to distinguishable particles. These unexpected non-zero probabilities are still present when non-separable Coulomb interaction or non-symmetrical potentials are considered. On the other hand, for initial wave packets close to Hamiltonian eigenstates, the usual zero two-particle probability for electrons at the same side of the barrier found in the literature is recovered. The generalization to many-particle scattering probabilities with quasi-particle wave packets for low and high phase-space density are also analyzed. The far-reaching consequences of these non-zero probabilities in the accurate evaluation of quantum noise in mesoscopic systems are briefly indicated.
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Affiliation(s)
- D Marian
- Dipartimento di Fisica dell'Università di Genova and INFN sezione di Genova, Via Dodecaneso 33, 16146 Genova, Italy
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14
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Cunden FD, Vivo P. Universal covariance formula for linear statistics on random matrices. PHYSICAL REVIEW LETTERS 2014; 113:070202. [PMID: 25170690 DOI: 10.1103/physrevlett.113.070202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 06/03/2023]
Abstract
We derive an analytical formula for the covariance cov(A,B) of two smooth linear statistics A=[under ∑]ia(λ_{i}) and B=[under ∑]ib(λ_{i}) to leading order for N→∞, where {λ_{i}} are the N real eigenvalues of a general one-cut random-matrix model with Dyson index β. The formula, carrying the universal 1/β prefactor, depends on the random-matrix ensemble only through the edge points [λ_{-},λ_{+}] of the limiting spectral density. For A=B, we recover in some special cases the classical variance formulas by Beenakker and by Dyson and Mehta, clarifying the respective ranges of applicability. Some choices of a(x) and b(x) lead to a striking decorrelation of the corresponding linear statistics. We provide two applications-the joint statistics of conductance and shot noise in ideal chaotic cavities, and some new fluctuation relations for traces of powers of random matrices.
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Affiliation(s)
- Fabio Deelan Cunden
- Dipartimento di Matematica, Università di Bari, I-70125 Bari, Italy and Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Bari, I-70126 Bari, Italy
| | - Pierpaolo Vivo
- Laboratoire de Physique Théorique et Modèles Statistiques (UMR 8626 du CNRS), Université Paris-Sud, Bâtiment 100, 91405 Orsay Cedex, France
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15
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Traversa FL, Zhan Z, Oriols X. Absorption and injection models for open time-dependent quantum systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:023304. [PMID: 25215848 DOI: 10.1103/physreve.90.023304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 06/03/2023]
Abstract
In the time-dependent simulation of pure states dealing with transport in open quantum systems, the initial state is located outside of the active region of interest. Using the superposition principle and the analytical knowledge of the free time evolution of such a state outside the active region, together with absorbing layers and remapping, a model for a very significant reduction of the computational burden associated with the numerical simulation of open time-dependent quantum systems is presented. The model is specially suited to study (many-particle and high-frequency effects) quantum transport, but it can also be applied to any other research field where the initial time-dependent pure state is located outside of the active region. From numerical simulations of open quantum systems described by the (effective mass) Schrödinger and (atomistic) tight-binding equations, a reduction of the computational burden of about two orders of magnitude for each spatial dimension of the domain with a negligible error is presented.
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Affiliation(s)
- F L Traversa
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193-Bellaterra (Barcelona), Spain
| | - Z Zhan
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193-Bellaterra (Barcelona), Spain
| | - X Oriols
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193-Bellaterra (Barcelona), Spain
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16
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Beenakker CWJ. Annihilation of colliding Bogoliubov quasiparticles reveals their Majorana nature. PHYSICAL REVIEW LETTERS 2014; 112:070604. [PMID: 24579584 DOI: 10.1103/physrevlett.112.070604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Indexed: 06/03/2023]
Abstract
The single-particle excitations of a superconductor are coherent superpositions of electrons and holes near the Fermi level, called Bogoliubov quasiparticles. They are Majorana fermions, meaning that pairs of quasiparticles can annihilate. We calculate the annihilation probability at a beam splitter for chiral quantum Hall edge states, obtaining a 1±cosϕ dependence on the phase difference ϕ of the superconductors from which the excitations originated (with the ± sign distinguishing singlet and triplet pairing). This provides for a nonlocal measurement of the superconducting phase in the absence of any supercurrent.
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Affiliation(s)
- C W J Beenakker
- Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands
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17
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Abstract
A measurement of the quantum-limited heat flow in an electronic conductor opens a pathway to the nanoscale control of heat currents.
[Also see Report by
Jezouin
et al.
]
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Affiliation(s)
- Björn Sothmann
- Département de Physique Théorique, Université de Genève, 24 quai Ernest Ansermet, CH-1211 Genève 4, Switzerland
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18
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Jezouin S, Parmentier FD, Anthore A, Gennser U, Cavanna A, Jin Y, Pierre F. Quantum Limit of Heat Flow Across a Single Electronic Channel. Science 2013; 342:601-4. [DOI: 10.1126/science.1241912] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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19
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Yu Y, Zhan H, Wan L, Wang B, Wei Y, Sun Q, Wang J. Shot noise of spin current and spin transfer torque. NANOTECHNOLOGY 2013; 24:155202. [PMID: 23519227 DOI: 10.1088/0957-4484/24/15/155202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report the theoretical investigation of the shot noise of the spin current (S(σ)) and the spin transfer torque (S(τ)) for non-collinear spin polarized transport in a spin-valve device which consists of a normal scattering region connected by two ferromagnetic electrodes (MNM system). Our theory was developed using the non-equilibrium Green's function method, and general nonlinear S(σ) - V and S(τ) - V relations were derived as a function of the angle θ between the magnetizations of two leads. We have applied our theory to a quantum dot system with a resonant level coupled with two ferromagnetic electrodes. It was found that, for the MNM system, the auto-correlation of the spin current is enough to characterize the fluctuation of the spin current. For a system with three ferromagnetic layers, however, both auto-correlation and cross-correlation of the spin current are needed to characterize the noise of the spin current. For a quantum dot with a resonant level, the derivative of spin torque with respect to bias voltage is proportional to sinθ when the system is far away from resonance. When the system is near resonance, the spin transfer torque becomes a non-sinusoidal function of θ. The derivative of the noise of the spin transfer torque with respect to the bias voltage Nτ behaves differently when the system is near or far away from resonance. Specifically, the differential shot noise of the spin transfer torque Nτ is a concave function of θ near resonance while it becomes a convex function of θ far away from resonance. For certain bias voltages, the period Nτ(θ) becomes π instead of 2π. For small θ, it was found that the differential shot noise of the spin transfer torque is very sensitive to the bias voltage and the other system parameters.
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Affiliation(s)
- Yunjin Yu
- College of Physics Science and Technology and Institute of Computational Condensed Matter Physics, Shenzhen University, Shenzhen, People's Republic of China
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20
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Hyldgaard P. Nonequilibrium thermodynamics of interacting tunneling transport: variational grand potential, density functional formulation and nature of steady-state forces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:424219. [PMID: 23032101 DOI: 10.1088/0953-8984/24/42/424219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The standard formulation of tunneling transport rests on an open-boundary modeling. There, conserving approximations to nonequilibrium Green function or quantum statistical mechanics provide consistent but computational costly approaches; alternatively, the use of density-dependent ballistic-transport calculations (e.g., Lang 1995 Phys. Rev. B 52 5335), here denoted 'DBT', provides computationally efficient (approximate) atomistic characterizations of the electron behavior but has until now lacked a formal justification. This paper presents an exact, variational nonequilibrium thermodynamic theory for fully interacting tunneling and provides a rigorous foundation for frozen-nuclei DBT calculations as a lowest-order approximation to an exact nonequilibrium thermodynamic density functional evaluation. The theory starts from the complete electron nonequilibrium quantum statistical mechanics and I identify the operator for the nonequilibrium Gibbs free energy which, generally, must be treated as an implicit solution of the fully interacting many-body dynamics. I demonstrate a minimal property of a functional for the nonequilibrium thermodynamic grand potential which thus uniquely identifies the solution as the exact nonequilibrium density matrix. I also show that the uniqueness-of-density proof from a closely related Lippmann-Schwinger collision density functional theory (Hyldgaard 2008 Phys. Rev. B 78 165109) makes it possible to express the variational nonequilibrium thermodynamic description as a single-particle formulation based on universal electron-density functionals; the full nonequilibrium single-particle formulation improves the DBT method, for example, by a more refined account of Gibbs free energy effects. I illustrate a formal evaluation of the zero-temperature thermodynamic grand potential value which I find is closely related to the variation in the scattering phase shifts and hence to Friedel density oscillations. This paper also discusses the difference between the here-presented exact thermodynamic forces and the often-used electrostatic forces. Finally the paper documents an inherent adiabatic nature of the thermodynamic forces and observes that these are suited for a nonequilibrium implementation of the Born-Oppenheimer approximation.
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Affiliation(s)
- P Hyldgaard
- Department of Microtechnology and Nanoscience, MC2, Chalmers University of Technology, SE-41296 Gothenburg, Sweden.
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21
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Vidal P, Kanzieper E. Statistics of reflection eigenvalues in chaotic cavities with nonideal leads. PHYSICAL REVIEW LETTERS 2012; 108:206806. [PMID: 23003168 DOI: 10.1103/physrevlett.108.206806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Indexed: 06/01/2023]
Abstract
The scattering matrix approach is employed to determine a joint probability density function of reflection eigenvalues for chaotic cavities coupled to the outside world through both ballistic and tunnel point contacts. Derived under assumption of broken time-reversal symmetry, this result is further utilized to (i) calculate the density and correlation functions of reflection eigenvalues, and (ii) analyze fluctuations properties of the Landauer conductance for the illustrative example of asymmetric chaotic cavity. Further extensions of the theory are pinpointed.
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Affiliation(s)
- Pedro Vidal
- Department of Applied Mathematics, H.I.T.-Holon Institute of Technology, Holon 58102, Israel
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22
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Albert M, Haack G, Flindt C, Büttiker M. Electron waiting times in mesoscopic conductors. PHYSICAL REVIEW LETTERS 2012; 108:186806. [PMID: 22681105 DOI: 10.1103/physrevlett.108.186806] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Indexed: 06/01/2023]
Abstract
Electron transport in mesoscopic conductors has traditionally involved investigations of the mean current and the fluctuations of the current. A complementary view on charge transport is provided by the distribution of waiting times between charge carriers, but a proper theoretical framework for coherent electronic systems has so far been lacking. Here we develop a quantum theory of electron waiting times in mesoscopic conductors expressed by a compact determinant formula. We illustrate our methodology by calculating the waiting time distribution for a quantum point contact and find a crossover from Wigner-Dyson statistics at full transmission to Poisson statistics close to pinch-off. Even when the low-frequency transport is noiseless, the electrons are not equally spaced in time due to their inherent wave nature. We discuss the implications for renewal theory in mesoscopic systems and point out several analogies with level spacing statistics and random matrix theory.
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Affiliation(s)
- Mathias Albert
- Département de Physique Théorique, Université de Genève, 1211 Genève, Switzerland
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23
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Bergfield JP, Barr JD, Stafford CA. Transmission eigenvalue distributions in highly conductive molecular junctions. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2012; 3:40-51. [PMID: 22428095 PMCID: PMC3304317 DOI: 10.3762/bjnano.3.5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 12/01/2011] [Indexed: 05/23/2023]
Abstract
BACKGROUND The transport through a quantum-scale device may be uniquely characterized by its transmission eigenvalues τ(n). Recently, highly conductive single-molecule junctions (SMJ) with multiple transport channels (i.e., several τ(n) > 0) have been formed from benzene molecules between Pt electrodes. Transport through these multichannel SMJs is a probe of both the bonding properties at the lead-molecule interface and of the molecular symmetry. RESULTS We use a many-body theory that properly describes the complementary wave-particle nature of the electron to investigate transport in an ensemble of Pt-benzene-Pt junctions. We utilize an effective-field theory of interacting π-electrons to accurately model the electrostatic influence of the leads, and we develop an ab initio tunneling model to describe the details of the lead-molecule bonding over an ensemble of junction geometries. We also develop a simple decomposition of transmission eigenchannels into molecular resonances based on the isolated resonance approximation, which helps to illustrate the workings of our many-body theory, and facilitates unambiguous interpretation of transmission spectra. CONCLUSION We confirm that Pt-benzene-Pt junctions have two dominant transmission channels, with only a small contribution from a third channel with τ(n) << 1. In addition, we demonstrate that the isolated resonance approximation is extremely accurate and determine that transport occurs predominantly via the HOMO orbital in Pt-benzene-Pt junctions. Finally, we show that the transport occurs in a lead-molecule coupling regime where the charge carriers are both particle-like and wave-like simultaneously, requiring a many-body description.
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Affiliation(s)
- Justin P Bergfield
- Departments of Chemistry and Physics, University of California, Irvine, California 92697, USA
| | - Joshua D Barr
- Department of Physics, University of Arizona, 1118 East Fourth Street, Tucson, AZ 85721, USA
| | - Charles A Stafford
- Department of Physics, University of Arizona, 1118 East Fourth Street, Tucson, AZ 85721, USA
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24
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Kaviraj B, Coupiac O, Courtois H, Lefloch F. Noise correlations in three-terminal diffusive superconductor-normal-metal-superconductor nanostructures. PHYSICAL REVIEW LETTERS 2011; 107:077005. [PMID: 21902422 DOI: 10.1103/physrevlett.107.077005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Indexed: 05/31/2023]
Abstract
We present measurements of current noise and cross correlations in three-terminal superconductor-normal-metal-superconductor (S-N-S) nanostructures that are potential solid-state entanglers thanks to Andreev reflections at the N-S interfaces. The noise-correlation measurements spanned from the regime where electron-electron interactions are relevant to the regime of incoherent multiple Andreev reflection. In the latter regime, negative cross correlations are observed in samples with closely spaced junctions.
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Affiliation(s)
- B Kaviraj
- SPSMS/LaTEQS, UMR-E, CEA-INAC, Grenoble, France
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25
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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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26
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Li J, Chu RL, Jain JK, Shen SQ. Topological Anderson insulator. PHYSICAL REVIEW LETTERS 2009; 102:136806. [PMID: 19392389 DOI: 10.1103/physrevlett.102.136806] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Indexed: 05/27/2023]
Abstract
Disorder plays an important role in two dimensions, and is responsible for striking phenomena such as metal-insulator transition and the integral and fractional quantum Hall effects. In this Letter, we investigate the role of disorder in the context of the recently discovered topological insulator, which possesses a pair of helical edge states with opposing spins moving in opposite directions and exhibits the phenomenon of quantum spin Hall effect. We predict an unexpected and nontrivial quantum phase termed "topological Anderson insulator," which is obtained by introducing impurities in a two-dimensional metal; here disorder not only causes metal-insulator transition, as anticipated, but is fundamentally responsible for creating extended edge states. We determine the phase diagram of the topological Anderson insulator and outline its experimental consequences.
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Affiliation(s)
- Jian Li
- Department of Physics and Center of Computational and Theoretical Physics, The University of Hong Kong, Pokfulam Road, Hong Kong
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27
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Osipov VA, Kanzieper E. Integrable theory of quantum transport in chaotic cavities. PHYSICAL REVIEW LETTERS 2008; 101:176804. [PMID: 18999772 DOI: 10.1103/physrevlett.101.176804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Indexed: 05/27/2023]
Abstract
The problem of quantum transport in chaotic cavities with broken time-reversal symmetry is shown to be completely integrable in the universal limit. This observation is utilized to determine the cumulants and the distribution function of conductance for a cavity with ideal leads supporting an arbitrary number n of propagating modes. Expressed in terms of solutions to the fifth Painlevé transcendent and/or the Toda lattice equation, the conductance distribution is further analyzed in the large-n limit that reveals long exponential tails in the otherwise Gaussian curve.
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Affiliation(s)
- Vladimir Al Osipov
- Department of Applied Mathematics, H.I.T.-Holon Institute of Technology, Holon, Israel
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28
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Lebedev AV, Lesovik GB, Blatter G. N-particle scattering matrix for electrons interacting on a quantum dot. PHYSICAL REVIEW LETTERS 2008; 100:226805. [PMID: 18643445 DOI: 10.1103/physrevlett.100.226805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Indexed: 05/26/2023]
Abstract
We present a nonperturbative expression for the scattering matrix of N particles interacting inside a quantum dot. Characterizing the dot by its resonances, we find a compact form for the scattering matrix in a real-time representation. We study the transmission probabilities and interaction-induced orbital entanglement of two electrons incident on the dot in a spin-singlet state.
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Affiliation(s)
- A V Lebedev
- Theoretische Physik, Schafmattstrasse 32, ETH-Zurich, CH-8093 Zürich, Switzerland
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29
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Youn SC, Lee HW, Sim HS. Nonequilibrium dephasing in an electronic Mach-Zehnder interferometer. PHYSICAL REVIEW LETTERS 2008; 100:196807. [PMID: 18518477 DOI: 10.1103/physrevlett.100.196807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Indexed: 05/26/2023]
Abstract
We study nonequilibrium dephasing in an electronic Mach-Zehnder interferometer. We demonstrate that the shot noise at the beam splitter of the interferometer generates an ensemble of nonequilibrium electron density configurations and that electron interactions induce configuration-specific phase shifts of an interfering electron. The resulting dephasing exhibits two characteristic features, a lobe pattern in the visibility and phase jumps of pi, in good agreement with experimental data.
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Affiliation(s)
- Seok-Chan Youn
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, Korea
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30
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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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31
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Zhang Y, DiCarlo L, McClure DT, Yamamoto M, Tarucha S, Marcus CM, Hanson MP, Gossard AC. Noise correlations in a Coulomb-blockaded quantum dot. PHYSICAL REVIEW LETTERS 2007; 99:036603. [PMID: 17678305 DOI: 10.1103/physrevlett.99.036603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Indexed: 05/16/2023]
Abstract
We report measurements of current noise auto- and cross correlation in a tunable quantum dot with two or three leads. As the Coulomb blockade is lifted at finite source-drain bias, the autocorrelation evolves from super- to sub-Poissonian in the two-lead case, and the cross correlation evolves from positive to negative in the three-lead case, consistent with transport through multiple levels. Cross correlations in the three-lead dot are found to be proportional to the noise in excess of the Poissonian value in the limit of weak output tunneling.
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Affiliation(s)
- Yiming Zhang
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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32
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Oriols X. Quantum-trajectory approach to time-dependent transport in mesoscopic systems with electron-electron interactions. PHYSICAL REVIEW LETTERS 2007; 98:066803. [PMID: 17358967 DOI: 10.1103/physrevlett.98.066803] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Indexed: 05/14/2023]
Abstract
It is proved that many-particle Bohm trajectories can be computed from single-particle time-dependent Schrödinger equations. From this result, a practical algorithm for the computation of transport properties of many-electron systems with exchange and Coulomb correlations is derived. As a test, two-particle Bohm trajectories in a tunneling scenario are compared to exact results with an excellent agreement. The algorithm opens the path for implementing a many-particle quantum transport (Monte Carlo) simulator, beyond the Fermi liquid paradigm.
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Affiliation(s)
- X Oriols
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.
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33
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McClure DT, Dicarlo L, Zhang Y, Engel HA, Marcus CM, Hanson MP, Gossard AC. Tunable noise cross correlations in a double quantum dot. PHYSICAL REVIEW LETTERS 2007; 98:056801. [PMID: 17358883 DOI: 10.1103/physrevlett.98.056801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Indexed: 05/14/2023]
Abstract
We report measurements of the cross correlation between temporal current fluctuations in two capacitively coupled quantum dots in the Coulomb blockade regime. The sign of the cross-spectral density is found to be tunable by gate voltage and source-drain bias. We find good agreement with the data by including an interdot Coulomb interaction in a sequential-tunneling model.
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Affiliation(s)
- D T McClure
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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34
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35
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Chen Y, Webb RA. Positive current correlations associated with super-Poissonian shot noise. PHYSICAL REVIEW LETTERS 2006; 97:066604. [PMID: 17026187 DOI: 10.1103/physrevlett.97.066604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Indexed: 05/12/2023]
Abstract
We report on shot noise cross spectrum measurements in a beam splitter configuration. Electrons tunneling through potential barriers are incident on a beam splitter and scattered into two separate channels. Such a partition process introduces correlations between the fluctuations of the two currents. Our work has confirmed that the generally expected negative correlations resulted from sub-Poissonian electron sources. More interestingly, positive cross correlations associated with barriers exhibiting super-Poissonian shot noise have also been observed. We have found that both positive and negative correlations can be related to the noise properties of the electron source.
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Affiliation(s)
- Yuanzhen Chen
- Department of Physics and USC NanoCenter, University of South Carolina, Columbia, South Carolina 29208, USA
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36
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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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37
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Komnik A, Saleur H. Full counting statistics of chiral Luttinger liquids with impurities. PHYSICAL REVIEW LETTERS 2006; 96:216406. [PMID: 16803262 DOI: 10.1103/physrevlett.96.216406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Indexed: 05/10/2023]
Abstract
We study the statistics of charge transfer through an impurity in a chiral Luttinger liquid (realized experimentally as a quantum point contact in a fractional quantum Hall edge state device). Taking advantage of the integrability we present a procedure for obtaining the cumulant generating function of the probability distribution to transfer a fixed amount of charge through the constriction. Using this approach we analyze in detail the behavior of the third cumulant C3 as a function of applied voltage, temperature, and barrier height. We predict that C3 can be used to measure the fractional charge at temperatures, which are several orders of magnitude higher than those needed to extract the fractional charge from the measurement of the second cumulant. Moreover, we identify the component of C3, which carries the information about the fractional charge.
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Affiliation(s)
- A Komnik
- Service de Physique Théorique, CEA Saclay, F-91191 Gif-sur-Yvette, France
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38
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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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39
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40
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Ma F, Wang S, Campbell JC. Shot noise suppression in avalanche photodiodes. PHYSICAL REVIEW LETTERS 2005; 95:176604. [PMID: 16383852 DOI: 10.1103/physrevlett.95.176604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Indexed: 05/05/2023]
Abstract
We identify a new shot noise suppression mechanism in a thin (approximately 100 nm) heterostructure avalanche photodiode. In the low-gain regime the shot noise is suppressed due to temporal correlations within amplified current pulses. We demonstrate in a Monte Carlo simulation that the effective excess noise factors can be < 1, and reconcile the apparent conflict between theory and experiments. This shot noise suppression mechanism is independent of known mechanisms such as Coulomb interaction, or reflection at heterojunction interfaces.
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Affiliation(s)
- Feng Ma
- Microelectronics Research Center, Department of Electrical and Computer Engineering, The University of Texas, Austin, Texas 78712, USA
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41
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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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42
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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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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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Cottet A, Belzig W, Bruder C. Positive cross correlations in a three-terminal quantum dot with ferromagnetic contacts. PHYSICAL REVIEW LETTERS 2004; 92:206801. [PMID: 15169373 DOI: 10.1103/physrevlett.92.206801] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2003] [Indexed: 05/24/2023]
Abstract
We study current fluctuations in an interacting three-terminal quantum dot with ferromagnetic leads. For appropriately polarized contacts, the transport through the dot is governed by dynamical spin blockade, i.e., a spin-dependent bunching of tunneling events not present in the paramagnetic case. This leads, for instance, to positive zero-frequency cross correlations of the currents in the output leads even in the absence of spin accumulation on the dot. We include the influence of spin-flip scattering and identify favorable conditions for the experimental observation of this effect with respect to polarization of the contacts and tunneling rates.
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Affiliation(s)
- A Cottet
- Department of Physics and Astronomy, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland
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Samuelsson P, Belzig W, Nazarov YV. Andreev reflection eigenvalue density in mesoscopic conductors. PHYSICAL REVIEW LETTERS 2004; 92:196807. [PMID: 15169435 DOI: 10.1103/physrevlett.92.196807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2003] [Indexed: 05/24/2023]
Abstract
The energy-dependent Andreev reflection eigenvalues determine the transport properties of normal-superconducting systems. We evaluate the eigenvalue density to get insight into the formation of resonant electron-hole transport channels. The circuit-theory-like method developed can be applied to any generic mesoscopic conductor or combinations thereof. We present the results for experimentally relevant cases of a diffusive wire and a double tunnel junction.
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Affiliation(s)
- P Samuelsson
- Département de Physique Theorique, Université de Genève, CH-1211 Genéve 4, Switzerland
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46
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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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47
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Beenakker CWJ, Emary C, Kindermann M, van Velsen JL. Proposal for production and detection of entangled electron-hole pairs in a degenerate electron gas. PHYSICAL REVIEW LETTERS 2003; 91:147901. [PMID: 14611554 DOI: 10.1103/physrevlett.91.147901] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2003] [Indexed: 05/24/2023]
Abstract
We demonstrate theoretically that the shot noise produced by a tunnel barrier in a two-channel conductor violates a Bell inequality. The nonlocality is shown to originate from entangled electron-hole pairs created by tunneling events-without requiring electron-electron interactions. The degree of entanglement (concurrence) equals 2(T1T2)(1/2)(T1+T2)(-1), with T1,T2<<1 the transmission eigenvalues. A pair of edge channels in the quantum Hall effect is proposed as an experimental realization.
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Affiliation(s)
- C W J Beenakker
- Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands
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48
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Safonov SS, Savchenko AK, Bagrets DA, Jouravlev ON, Nazarov YV, Linfield EH, Ritchie DA. Enhanced shot noise in resonant tunneling via interacting localized states. PHYSICAL REVIEW LETTERS 2003; 91:136801. [PMID: 14525327 DOI: 10.1103/physrevlett.91.136801] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2003] [Indexed: 05/24/2023]
Abstract
In a variety of mesoscopic systems shot noise is seen to be suppressed in comparison with its Poisson value. In this work we observe a considerable enhancement of shot noise in the case of resonant tunneling via localized states. We present a model of correlated transport through two localized states which provides both a qualitative and a quantitative description of this effect.
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Affiliation(s)
- S S Safonov
- School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, United Kingdom
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49
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Schanz H, Puhlmann M, Geisel T. Shot noise in chaotic cavities from action correlations. PHYSICAL REVIEW LETTERS 2003; 91:134101. [PMID: 14525306 DOI: 10.1103/physrevlett.91.134101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2003] [Indexed: 05/24/2023]
Abstract
We consider universal shot noise in ballistic chaotic cavities from a semiclassical point of view and show that it is due to action correlations within certain groups of classical trajectories. Using quantum graphs as a model system, we sum these trajectories analytically and find agreement with random-matrix theory. Unlike all action correlations which have been considered before, the correlations relevant for shot noise involve four trajectories and do not depend on the presence of any symmetry.
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Affiliation(s)
- Holger Schanz
- Max-Planck-Institut für Strömungsforschung, Göttingen, Germany.
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50
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Reydellet LH, Roche P, Glattli DC, Etienne B, Jin Y. Quantum partition noise of photon-created electron-hole pairs. PHYSICAL REVIEW LETTERS 2003; 90:176803. [PMID: 12786091 DOI: 10.1103/physrevlett.90.176803] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2002] [Indexed: 05/24/2023]
Abstract
We show experimentally that even when no bias voltage is applied to a quantum conductor, the electronic quantum partition noise can be investigated with GHz radio frequency excitation. Using a quantum point contact configuration as the ballistic conductor we are able to make an accurate determination of the partition noise Fano factor resulting from the photon-assisted shot noise. Applying both voltage bias and rf irradiation we are able to make a definitive quantitative test of the scattering theory of photon-assisted shot noise.
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Affiliation(s)
- L-H Reydellet
- Service de Physique de l'Etat Condensé, CEA Saclay, F-91191 Gif-Sur-Yvette, France
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