1
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Burenev IN, Majumdar SN, Rosso A. Importance sampling for counting statistics in one-dimensional systems. J Chem Phys 2024; 161:054115. [PMID: 39105548 DOI: 10.1063/5.0221076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Accepted: 07/19/2024] [Indexed: 08/07/2024] Open
Abstract
In this paper, we consider the problem of numerical investigation of the counting statistics for a class of one-dimensional systems. Importance sampling, the cornerstone technique usually implemented for such problems, critically hinges on selecting an appropriate biased distribution. While an exponential tilt in the observable stands as the conventional choice for various problems, its efficiency in the context of counting statistics may be significantly hindered by the genuine discreteness of the observable. To address this challenge, we propose an alternative strategy, which we call importance sampling with the local tilt. We demonstrate the efficiency of the proposed approach through the analysis of three prototypical examples: a set of independent Gaussian random variables, Dyson gas, and symmetric simple exclusion process with a steplike initial condition.
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Affiliation(s)
- Ivan N Burenev
- LPTMS, CNRS, Université Paris-Saclay, 91405 Orsay, France
| | | | - Alberto Rosso
- LPTMS, CNRS, Université Paris-Saclay, 91405 Orsay, France
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2
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Madrid I, Zheng Z, Gerbelot C, Fujiwara A, Li S, Grall S, Nishiguchi K, Kim SH, Chovin A, Demaille C, Clement N. Ballistic Brownian Motion of Nanoconfined DNA. ACS NANO 2023; 17:17031-17040. [PMID: 37700490 DOI: 10.1021/acsnano.3c04349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
Theoretical treatments of polymer dynamics in liquid generally start with the basic assumption that motion at the smallest scale is heavily overdamped; therefore, inertia can be neglected. We report on the Brownian motion of tethered DNA under nanoconfinement, which was analyzed by molecular dynamics simulation and nanoelectrochemistry-based single-electron shuttle experiments. Our results show a transition into the ballistic Brownian motion regime for short DNA in sub-5 nm gaps, with quality coefficients as high as 2 for double-stranded DNA, an effect mainly attributed to a drastic increase in stiffness. The possibility for DNA to enter the underdamped regime could have profound implications on our understanding of the energetics of biomolecular engines such as the replication machinery, which operates in nanocavities that are a few nanometers wide.
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Affiliation(s)
- Ignacio Madrid
- IIS, LIMMS CNRS-IIS UMI2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo 153-8505, Japan
| | - Zhiyong Zheng
- Laboratoire d'Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Cedric Gerbelot
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi-shi 243-0198, Japan
| | - Akira Fujiwara
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi-shi 243-0198, Japan
| | - Shuo Li
- IIS, LIMMS CNRS-IIS UMI2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo 153-8505, Japan
| | - Simon Grall
- IIS, LIMMS CNRS-IIS UMI2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo 153-8505, Japan
| | - Katsuhiko Nishiguchi
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi-shi 243-0198, Japan
| | - Soo Hyeon Kim
- IIS, LIMMS CNRS-IIS UMI2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo 153-8505, Japan
| | - Arnaud Chovin
- Laboratoire d'Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Christophe Demaille
- Laboratoire d'Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France
| | - Nicolas Clement
- IIS, LIMMS CNRS-IIS UMI2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo 153-8505, Japan
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi-shi 243-0198, Japan
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3
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Lucena IRAC, Batista RA, Ramos JGGS. Thermodynamic uncertainty relations in mesoscopic devices. Phys Rev E 2023; 107:064104. [PMID: 37464637 DOI: 10.1103/physreve.107.064104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 05/15/2023] [Indexed: 07/20/2023]
Abstract
We investigate the thermodynamic uncertainty relations (TURs) in mesoscopic devices for all universal symmetry classes of Wigner-Dyson and Dirac (chiral). The observables of interest include the TUR (MS), which is defined in terms of the ratio between the mean noise and mean conductance, as well as a new TUR (R) proposed in this article, which is based on the ensemble mean of the noise-to-conductance ratio. A detailed study is made on the quantum interference corrections associated with the TURs. We also analyze the influence of orbital and sublattice/chiral degrees of freedom for the validity of the observables in these chaotic mesoscopic billiards. Our investigation is based on the concatenation between the Landauer-Büttiker theory, the Mahaux-Wendeinmüller theory, and the TURs. We simulate the universal mesoscopic chaotic quantum dots using the random-matrix theory and compare our numerical results with the pertinent experimental data. The results were obtained for a different number of channels and tunneling rates that vary from the opaque to the ideal regime and, in all cases, demonstrate a clear phenomenological distinction between the TURs. In particular, the opaque regime engenders remarkable differences between the observables, even in the semiclassical regime, which characterizes a clear violation of the central limit theorem. Furthermore, we show that the phenomenology of the quantum interference corrections is strikingly robust, surprisingly exhibiting an order of magnitude greater than the supposedly leading semiclassical term for the TUR (R).
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Affiliation(s)
- I R A C Lucena
- Departamento de Física, Universidade Federal da Paraíba, 58051-970 Joaão Pessoa, Paraíba, Brazil
| | - R A Batista
- Departamento de Física, Universidade Federal da Paraíba, 58051-970 Joaão Pessoa, Paraíba, Brazil
| | - J G G S Ramos
- Departamento de Física, Universidade Federal da Paraíba, 58051-970 Joaão Pessoa, Paraíba, Brazil
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4
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Han C, Meir Y, Sela E. Realistic Protocol to Measure Entanglement at Finite Temperatures. PHYSICAL REVIEW LETTERS 2023; 130:136201. [PMID: 37067316 DOI: 10.1103/physrevlett.130.136201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 03/14/2023] [Indexed: 06/19/2023]
Abstract
It is desirable to relate entanglement of many-body systems to measurable observables. In systems with a conserved charge, it was recently shown that the number entanglement entropy (NEE)-i.e., the entropy change due to an unselective subsystem charge measurement-is an entanglement monotone. Here we derive finite-temperature equilibrium relations between Rényi moments of the NEE, and multipoint charge correlations. These relations are exemplified in quantum dot systems where the desired charge correlations can be measured via a nearby quantum point contact. In quantum dots recently realizing the multichannel Kondo effect we show that the NEE has a nontrivial universal temperature dependence which is now accessible using the proposed methods.
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Affiliation(s)
- Cheolhee Han
- School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yigal Meir
- Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva, 84105 Israel
- Department of Physics, Princeton University, Princeton, New Jersey 08540, USA
| | - Eran Sela
- School of Physics and Astronomy, Tel Aviv University, Tel Aviv 6997801, Israel
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5
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Post-processing of real-time quantum event measurements for an optimal bandwidth. Sci Rep 2023; 13:1105. [PMID: 36670214 PMCID: PMC9859797 DOI: 10.1038/s41598-023-28273-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 01/16/2023] [Indexed: 01/22/2023] Open
Abstract
Single electron tunneling and its transport statistics have been studied for some time using high precision charge detectors. However, this type of detection requires advanced lithography, optimized material systems and low temperatures (mK). A promising alternative, recently demonstrated, is to exploit an optical transition that is turned on or off when a tunnel event occurs. High bandwidths should be achievable with this approach, although this has not been adequately investigated so far. We have studied low temperature resonance fluorescence from a self-assembled quantum dot embedded in a diode structure. We detect single photons from the dot in real time and evaluate the recorded data only after the experiment, using post-processing to obtain the random telegraph signal of the electron transport. This is a significant difference from commonly used charge detectors and allows us to determine the optimal time resolution for analyzing our data. We show how this post-processing affects both the determination of tunneling rates using waiting-time distributions and statistical analysis using full-counting statistics. We also demonstrate, as an example, that we can analyze our data with bandwidths as high as 175 kHz. Using a simple model, we discuss the limiting factors for achieving the optimal bandwidth and propose how a time resolution of more than 1 MHz could be achieved.
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6
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Salazar DSP. Thermodynamic skewness relation from detailed fluctuation theorem. Phys Rev E 2022; 106:L042101. [PMID: 36397555 DOI: 10.1103/physreve.106.l042101] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 09/21/2022] [Indexed: 06/16/2023]
Abstract
The detailed fluctuation theorem (DFT) is a statement about the asymmetry in the statistics of the entropy production. Consequences of the DFT are the second law of thermodynamics and the thermodynamics uncertainty relation, which translate into lower bounds for the mean and variance of currents, respectively. However, far from equilibrium, mean and variance are not enough to characterize the underlying distribution of the entropy production. The fluctuations are not necessarily Gaussian (nor symmetric), which means their skewness could be nonzero. We prove that the DFT imposes a negative tight lower bound for the skewness of the entropy production as a function of the mean. As application, we check the bound in the heat exchange problem between two thermal reservoirs mediated by a qubit swap engine.
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Affiliation(s)
- Domingos S P Salazar
- Unidade de Educação a Distância e Tecnologia, Universidade Federal Rural de Pernambuco, 52171-900 Recife, Pernambuco, Brazil
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7
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Ptaszyński K. Bounds on skewness and kurtosis of steady-state currents. Phys Rev E 2022; 106:024119. [PMID: 36109909 DOI: 10.1103/physreve.106.024119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Current fluctuations are a powerful tool to unravel the underlying physics of the observed transport process. This work discusses some general properties of the third and the fourth current cumulant (skewness and kurtosis) related to dynamics and thermodynamics of a transport setup. Specifically, several distinct bounds on these quantities are either analytically derived or numerically conjectured, which are applicable to (1) noninteracting fermionic systems, (2) noninteracting bosonic systems, (3) thermally driven classical Markovian systems, and (4) unicyclic Markovian networks. Finally, it is demonstrated that violation of the obtained inequalities can provide a broad spectrum of information about the physics of the analyzed system; e.g., it can enable one to infer the presence of interactions or unitary dynamics, unravel the topology of the Markovian network, or characterize the nature of thermodynamic forces driving the system. In particular, relevant information about the microscopic dynamics can be gained even at equilibrium when the current variance-a standard measure of current fluctuations-is determined mostly by the thermal noise.
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Affiliation(s)
- Krzysztof Ptaszyński
- Institute of Molecular Physics, Polish Academy of Sciences, Mariana Smoluchowskiego 17, 60-179 Poznań, Poland
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8
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Kleinherbers E, Stegmann P, Kurzmann A, Geller M, Lorke A, König J. Pushing the Limits in Real-Time Measurements of Quantum Dynamics. PHYSICAL REVIEW LETTERS 2022; 128:087701. [PMID: 35275653 DOI: 10.1103/physrevlett.128.087701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
Time-resolved studies of quantum systems are the key to understanding quantum dynamics at its core. The real-time measurement of individual quantum numbers as they switch between certain discrete values, well known as a "random telegraph signal," is expected to yield maximal physical insight. However, the signal suffers from both systematic errors, such as a limited time resolution and noise from the measurement apparatus, as well as statistical errors due to a limited amount of data. Here we demonstrate that an evaluation scheme based on factorial cumulants can reduce the influence of such errors by orders of magnitude. The error resilience is supported by a general theory for the detection errors as well as experimental data of single-electron tunneling through a self-assembled quantum dot. Thus, factorial cumulants push the limits in the analysis of random telegraph data, which represent a wide class of experiments in physics, chemistry, engineering, and life sciences.
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Affiliation(s)
- E Kleinherbers
- Faculty of Physics and CENIDE, University of Duisburg-Essen, 47057 Duisburg, Germany
| | - P Stegmann
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - A Kurzmann
- 2nd Institute of Physics, RWTH Aachen University, 52074 Aachen, Germany
| | - M Geller
- Faculty of Physics and CENIDE, University of Duisburg-Essen, 47057 Duisburg, Germany
| | - A Lorke
- Faculty of Physics and CENIDE, University of Duisburg-Essen, 47057 Duisburg, Germany
| | - J König
- Faculty of Physics and CENIDE, University of Duisburg-Essen, 47057 Duisburg, Germany
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9
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Kamijima T, Otsubo S, Ashida Y, Sagawa T. Higher-order efficiency bound and its application to nonlinear nanothermoelectrics. Phys Rev E 2021; 104:044115. [PMID: 34781477 DOI: 10.1103/physreve.104.044115] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 09/22/2021] [Indexed: 11/07/2022]
Abstract
Power and efficiency of heat engines are two conflicting objectives. A tight efficiency bound is expected to give insights on the fundamental properties of such a power-efficiency tradeoff. Here, we derive an upper bound on the efficiency of steady-state heat engines, which incorporates higher-order fluctuations of power. In a prototypical model of nonlinear nanostructured thermoelectrics, we show that the obtained bound is tighter than a well-established efficiency bound derived from the thermodynamic uncertainty relation, demonstrating that the higher-order terms have rich information about the thermodynamic efficiency in the nonlinear regime. In particular, we find that the higher-order bound is exactly achieved if the tight coupling condition is satisfied. The obtained bound gives a consistent prediction with an observation that nonlinearity enhances the power-efficiency tradeoff, and would also be useful in a variety of nanoscale engines.
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Affiliation(s)
- Takuya Kamijima
- Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Shun Otsubo
- Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Yuto Ashida
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.,Institute for Physics of Intelligence, University of Tokyo, 7-3-1 Hongo, Tokyo 113-0033, Japan
| | - Takahiro Sagawa
- Department of Applied Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.,Quantum-Phase Electronics Center (QPEC), The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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10
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Smith NR, Le Doussal P, Majumdar SN, Schehr G. Counting statistics for noninteracting fermions in a d-dimensional potential. Phys Rev E 2021; 103:L030105. [PMID: 33862753 DOI: 10.1103/physreve.103.l030105] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 03/03/2021] [Indexed: 11/07/2022]
Abstract
We develop a first-principles approach to compute the counting statistics in the ground state of N noninteracting spinless fermions in a general potential in arbitrary dimensions d (central for d>1). In a confining potential, the Fermi gas is supported over a bounded domain. In d=1, for specific potentials, this system is related to standard random matrix ensembles. We study the quantum fluctuations of the number of fermions N_{D} in a domain D of macroscopic size in the bulk of the support. We show that the variance of N_{D} grows as N^{(d-1)/d}(A_{d}logN+B_{d}) for large N, and obtain the explicit dependence of A_{d},B_{d} on the potential and on the size of D (for a spherical domain in d>1). This generalizes the free-fermion results for microscopic domains, given in d=1 by the Dyson-Mehta asymptotics from random matrix theory. This leads us to conjecture similar asymptotics for the entanglement entropy of the subsystem D, in any dimension, supported by exact results for d=1.
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Affiliation(s)
- Naftali R Smith
- LPTMS, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Pierre Le Doussal
- CNRS-Laboratoire de Physique Théorique de l'Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex, France
| | - Satya N Majumdar
- LPTMS, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Grégory Schehr
- LPTMS, CNRS, Université Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
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11
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Hussein R, Kohler S, Bayer JC, Wagner T, Haug RJ. Spectral Properties of Stochastic Resonance in Quantum Transport. PHYSICAL REVIEW LETTERS 2020; 125:206801. [PMID: 33258637 DOI: 10.1103/physrevlett.125.206801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/15/2020] [Indexed: 06/12/2023]
Abstract
We investigate theoretically and experimentally stochastic resonance in a quantum dot coupled to electron source and drain via time-dependent tunnel barriers. A central finding is a transition visible in the current noise spectrum as a bifurcation of a dip originally at zero frequency. The transition occurs close to the stochastic resonance working point and relates to quantized pumping. For the evaluation of power spectra from measured waiting times, we generalize a result from renewal theory to the ac-driven case. Moreover, we develop a master equation method to obtain phase-averaged current noise spectra for driven quantum transport.
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Affiliation(s)
- Robert Hussein
- Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany
| | - Sigmund Kohler
- Instituto de Ciencia de Materiales de Madrid, CSIC, E-28049 Madrid, Spain
| | - Johannes C Bayer
- Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hanover, Germany
| | - Timo Wagner
- Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hanover, Germany
| | - Rolf J Haug
- Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hanover, Germany
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12
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El Abbassi M, Perrin ML, Barin GB, Sangtarash S, Overbeck J, Braun O, Lambert CJ, Sun Q, Prechtl T, Narita A, Müllen K, Ruffieux P, Sadeghi H, Fasel R, Calame M. Controlled Quantum Dot Formation in Atomically Engineered Graphene Nanoribbon Field-Effect Transistors. ACS NANO 2020; 14:5754-5762. [PMID: 32223259 PMCID: PMC7254832 DOI: 10.1021/acsnano.0c00604] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/30/2020] [Indexed: 05/29/2023]
Abstract
Graphene nanoribbons (GNRs) have attracted strong interest from researchers worldwide, as they constitute an emerging class of quantum-designed materials. The major challenges toward their exploitation in electronic applications include reliable contacting, complicated by their small size (<50 nm), and the preservation of their physical properties upon device integration. In this combined experimental and theoretical study, we report on the quantum dot behavior of atomically precise GNRs integrated in a device geometry. The devices consist of a film of aligned five-atom-wide GNRs (5-AGNRs) transferred onto graphene electrodes with a sub 5 nm nanogap. We demonstrate that these narrow-bandgap 5-AGNRs exhibit metal-like behavior at room temperature and single-electron transistor behavior for temperatures below 150 K. By performing spectroscopy of the molecular levels at 13 K, we obtain addition energies in the range of 200-300 meV. DFT calculations predict comparable addition energies and reveal the presence of two electronic states within the bandgap of infinite ribbons when the finite length of the 5-AGNR is accounted for. By demonstrating the preservation of the 5-AGNRs' molecular levels upon device integration, as demonstrated by transport spectroscopy, our study provides a critical step forward in the realization of more exotic GNR-based nanoelectronic devices.
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Affiliation(s)
- Maria El Abbassi
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
- Department
of Physics, University of Basel, CH-4056 Basel, Switzerland
- Kavli
Institute of Nanoscience, Delft University
of Technology, 2628 CJ Delft, The Netherlands
| | - Mickael L. Perrin
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Gabriela Borin Barin
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Sara Sangtarash
- Department
of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
- School of
Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Jan Overbeck
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
- Department
of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - Oliver Braun
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
- Department
of Physics, University of Basel, CH-4056 Basel, Switzerland
| | - Colin J. Lambert
- Department
of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Qiang Sun
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | | | - Akimitsu Narita
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Klaus Müllen
- Max
Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Pascal Ruffieux
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
| | - Hatef Sadeghi
- Department
of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
- School of
Engineering, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Roman Fasel
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
- Department
of Chemistry and Biochemistry, University
of Bern, CH-3012 Bern, Switzerland
| | - Michel Calame
- Empa,
Swiss Federal Laboratories for Materials Science and Technology, CH-8600 Dübendorf, Switzerland
- Department
of Physics, University of Basel, CH-4056 Basel, Switzerland
- Swiss
Nanoscience Institute, University of Basel, CH-4056 Basel, Switzerland
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13
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Lochner P, Kurzmann A, Kerski J, Stegmann P, König J, Wieck AD, Ludwig A, Lorke A, Geller M. Real-Time Detection of Single Auger Recombination Events in a Self-Assembled Quantum Dot. NANO LETTERS 2020; 20:1631-1636. [PMID: 32023065 DOI: 10.1021/acs.nanolett.9b04650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Auger recombination is a nonradiative process, where the recombination energy of an electron-hole pair is transferred to a third charge carrier. It is a common effect in colloidal quantum dots that quenches the radiative emission with an Auger recombination time below nanoseconds. In self-assembled QDs, the Auger recombination has been observed with a much longer recombination time on the order of microseconds. Here, we use two-color laser excitation on the exciton and trion transition in resonance fluorescence on a single self-assembled quantum dot to monitor in real-time single quantum events of the Auger process. Full counting statistics on the random telegraph signal give access to the cumulants and demonstrate the tunability of the Fano factor from a Poissonian to a sub-Poissonian distribution by Auger-mediated electron emission from the dot. Therefore, the Auger process can be used to tune optically the charge carrier occupation of the dot by the incident laser intensity, independently from the electron tunneling from the reservoir by the gate voltage. Our findings are not only highly relevant for the understanding of the Auger process but also demonstrate the perspective of the Auger effect for controlling precisely the charge state in a quantum system by optical means.
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Affiliation(s)
- Pia Lochner
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Annika Kurzmann
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
- Solid State Physics Laboratory, ETH Zurich, Otto-Stern-Weg 1, 8093 Zurich, Switzerland
| | - Jens Kerski
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Philipp Stegmann
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Jürgen König
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Andreas D Wieck
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraβe 150, 44780 Bochum, Germany
| | - Arne Ludwig
- Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Universitätsstraβe 150, 44780 Bochum, Germany
| | - Axel Lorke
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
| | - Martin Geller
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstr. 1, 47057 Duisburg, Germany
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14
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Kurzmann A, Overweg H, Eich M, Pally A, Rickhaus P, Pisoni R, Lee Y, Watanabe K, Taniguchi T, Ihn T, Ensslin K. Charge Detection in Gate-Defined Bilayer Graphene Quantum Dots. NANO LETTERS 2019; 19:5216-5221. [PMID: 31311270 DOI: 10.1021/acs.nanolett.9b01617] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on charge detection in electrostatically defined quantum dot devices in bilayer graphene using an integrated charge detector. The device is fabricated without any etching and features a graphite back gate, leading to high-quality quantum dots. The charge detector is based on a second quantum dot separated from the first dot by depletion underneath a 150 nm wide gate. We show that Coulomb resonances in the sensing dot are sensitive to individual charging events on the nearby quantum dot. The potential change due to single electron charging causes a steplike change (up to 77%) in the current through the charge detector. Furthermore, the charging states of a quantum dot with tunable tunneling barriers and of coupled quantum dots can be detected.
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Affiliation(s)
- Annika Kurzmann
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
| | - Hiske Overweg
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
| | - Marius Eich
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
| | - Alessia Pally
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
| | - Peter Rickhaus
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
| | - Riccardo Pisoni
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
| | - Yongjin Lee
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
| | - Kenji Watanabe
- National Institute for Material Science , 1-1 Namiki , Tsukuba 30-0044 , Japan
| | - Takashi Taniguchi
- National Institute for Material Science , 1-1 Namiki , Tsukuba 30-0044 , Japan
| | - Thomas Ihn
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
| | - Klaus Ensslin
- Solid State Physics Laboratory , ETH Zürich , CH-8093 Zürich , Switzerland
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15
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Rudge SL, Kosov DS. Counting quantum jumps: A summary and comparison of fixed-time and fluctuating-time statistics in electron transport. J Chem Phys 2019; 151:034107. [DOI: 10.1063/1.5108518] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Samuel L. Rudge
- College of Science and Engineering, James Cook University, Townsville, QLD, 4814, Australia
| | - Daniel S. Kosov
- College of Science and Engineering, James Cook University, Townsville, QLD, 4814, Australia
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16
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Kurzmann A, Stegmann P, Kerski J, Schott R, Ludwig A, Wieck AD, König J, Lorke A, Geller M. Optical Detection of Single-Electron Tunneling into a Semiconductor Quantum Dot. PHYSICAL REVIEW LETTERS 2019; 122:247403. [PMID: 31322370 DOI: 10.1103/physrevlett.122.247403] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Indexed: 06/10/2023]
Abstract
The maximum information of a dynamic quantum system is given by real-time detection of every quantum event, where the ultimate challenge is a stable, sensitive detector with high bandwidth. All physical information can then be drawn from a statistical analysis of the time traces. We demonstrate here an optical detection scheme based on the time-resolved resonance fluorescence on a single quantum dot. Single-electron resolution with high signal-to-noise ratio (4σ confidence) and high bandwidth of 10 kHz make it possible to record the individual quantum events of the transport dynamics. Full counting statistics with factorial cumulants gives access to the nonequilibrium dynamics of spin relaxation of a singly charged dot (γ_{↑↓}=3 ms^{-1}), even in an equilibrium transport measurement.
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Affiliation(s)
- A Kurzmann
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany
- Solid State Physics Laboratory, ETH Zurich, 8093 Zurich, Switzerland
| | - P Stegmann
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany
| | - J Kerski
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany
| | - R Schott
- Chair for Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - A Ludwig
- Chair for Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - A D Wieck
- Chair for Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - J König
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany
| | - A Lorke
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany
| | - M Geller
- Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg, Germany
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17
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Singh S, Menczel P, Golubev DS, Khaymovich IM, Peltonen JT, Flindt C, Saito K, Roldán É, Pekola JP. Universal First-Passage-Time Distribution of Non-Gaussian Currents. PHYSICAL REVIEW LETTERS 2019; 122:230602. [PMID: 31298917 DOI: 10.1103/physrevlett.122.230602] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Indexed: 06/10/2023]
Abstract
We investigate the fluctuations of the time elapsed until the electric charge transferred through a conductor reaches a given threshold value. For this purpose, we measure the distribution of the first-passage times for the net number of electrons transferred between two metallic islands in the Coulomb blockade regime. Our experimental results are in excellent agreement with numerical calculations based on a recent theory describing the exact first-passage-time distributions for any nonequilibrium stationary Markov process. We also derive a simple analytical approximation for the first-passage-time distribution, which takes into account the non-Gaussian statistics of the electron transport, and show that it describes the experimental distributions with high accuracy. This universal approximation describes a wide class of stochastic processes, and can be used beyond the context of mesoscopic charge transport. In addition, we verify experimentally a fluctuation relation between the first-passage-time distributions for positive and negative thresholds.
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Affiliation(s)
- Shilpi Singh
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Finland
| | - Paul Menczel
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Finland
| | - Dmitry S Golubev
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Finland
| | - Ivan M Khaymovich
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Strasse 38, 01187 Dresden, Germany
- Institute for Physics of Microstructures, Russian Academy of Sciences, 603950 Nizhny Novgorod, GSP-105, Russia
| | - Joonas T Peltonen
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Finland
| | - Christian Flindt
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Finland
| | - Keiji Saito
- Department of Physics, Keio University-Yokohama 2238522, Japan
| | - Édgar Roldán
- The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste, Italy
| | - Jukka P Pekola
- QTF Centre of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Finland
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18
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Kilgour M, Agarwalla BK, Segal D. Path-integral methodology and simulations of quantum thermal transport: Full counting statistics approach. J Chem Phys 2019; 150:084111. [PMID: 30823775 DOI: 10.1063/1.5084949] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We develop and test a computational framework to study heat exchange in interacting, nonequilibrium open quantum systems. Our iterative full counting statistics path integral (iFCSPI) approach extends a previously well-established influence functional path integral method, by going beyond reduced system dynamics to provide the cumulant generating function of heat exchange. The method is straightforward; we implement it for the nonequilibrium spin boson model to calculate transient and long-time observables, focusing on the steady-state heat current flowing through the system under a temperature difference. Results are compared to perturbative treatments and demonstrate good agreement in the appropriate limits. The challenge of converging nonequilibrium quantities, currents and high order cumulants, is discussed in detail. The iFCSPI, a numerically exact technique, naturally captures strong system-bath coupling and non-Markovian effects of the environment. As such, it is a promising tool for probing fundamental questions in quantum transport and quantum thermodynamics.
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Affiliation(s)
- Michael Kilgour
- Chemical Physics Theory Group, Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario M5S 3H6, Canada
| | - Bijay Kumar Agarwalla
- Department of Physics, Indian Institute of Science Education and Research, Dr. Homi Bhaba Road, Pune, India
| | - Dvira Segal
- Chemical Physics Theory Group, Department of Chemistry, University of Toronto, 80 Saint George St., Toronto, Ontario M5S 3H6, Canada
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19
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Sahputra IH, Alexiadis A, Adams MJ. Effects of Moisture on the Mechanical Properties of Microcrystalline Cellulose and the Mobility of the Water Molecules as Studied by the Hybrid Molecular Mechanics-Molecular Dynamics Simulation Method. ACTA ACUST UNITED AC 2019. [DOI: 10.1002/polb.24801] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Iwan H. Sahputra
- School of Chemical Engineering; University of Birmingham; Birmingham United Kingdom
| | - Alessio Alexiadis
- School of Chemical Engineering; University of Birmingham; Birmingham United Kingdom
| | - Michael J. Adams
- School of Chemical Engineering; University of Birmingham; Birmingham United Kingdom
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20
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Giri SK, Goswami HP. Nonequilibrium fluctuations of a driven quantum heat engine via machine learning. Phys Rev E 2019; 99:022104. [PMID: 30934252 DOI: 10.1103/physreve.99.022104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Indexed: 11/07/2022]
Abstract
We propose a machine-learning approach based on artificial neural network to efficiently obtain new insights on the role of geometric contributions to the nonequilibrium fluctuations of an adiabatically temperature-driven quantum heat engine coupled to a cavity. Using the artificial neural network we have explored the interplay between bunched and antibunched photon exchange statistics for different engine parameters. We report that beyond a pivotal cavity temperature, the Fano factor oscillates between giant and low values as a function of phase difference between the driving protocols. We further observe that the standard thermodynamic uncertainty relation is not valid when there are finite geometric contributions to the fluctuations but holds true for zero phase difference even in the presence of coherences.
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Affiliation(s)
- Sajal Kumar Giri
- Finite Systems Division, Max-Planck-Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden, Germany
| | - Himangshu Prabal Goswami
- Finite Systems Division, Max-Planck-Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden, Germany.,Department of Chemical Sciences, Tezpur University, Napaam, Tezpur 784028, Assam, India
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21
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Kraft R, Krainov IV, Gall V, Dmitriev AP, Krupke R, Gornyi IV, Danneau R. Valley Subband Splitting in Bilayer Graphene Quantum Point Contacts. PHYSICAL REVIEW LETTERS 2018; 121:257703. [PMID: 30608811 DOI: 10.1103/physrevlett.121.257703] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Indexed: 06/09/2023]
Abstract
We report a study of one-dimensional subband splitting in a bilayer graphene quantum point contact in which quantized conductance in steps of 4e^{2}/h is clearly defined down to the lowest subband. While our source-drain bias spectroscopy measurements reveal an unconventional confinement, we observe a full lifting of the valley degeneracy at high magnetic fields perpendicular to the bilayer graphene plane for the first two lowest subbands where confinement and Coulomb interactions are the strongest and a peculiar merging or mixing of K and K^{'} valleys from two nonadjacent subbands with indices (N,N+2), which are well described by our semiphenomenological model.
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Affiliation(s)
- R Kraft
- Institute of Nanotechnology, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
| | - I V Krainov
- A.F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia
- Lappeenranta University of Technology, P.O. Box 20, 53851 Lappeenranta, Finland
| | - V Gall
- Institute of Nanotechnology, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
- Institute for Condensed Matter Theory, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
| | - A P Dmitriev
- A.F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia
| | - R Krupke
- Institute of Nanotechnology, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
- Department of Materials and Earth Sciences, Technical University Darmstadt, 64287 Darmstadt, Germany
| | - I V Gornyi
- Institute of Nanotechnology, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
- A.F. Ioffe Physico-Technical Institute, 194021 St. Petersburg, Russia
- Institute for Condensed Matter Theory, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
| | - R Danneau
- Institute of Nanotechnology, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany
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22
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Kosov DS. Waiting time between charging and discharging processes in molecular junctions. J Chem Phys 2018; 149:164105. [PMID: 30384714 DOI: 10.1063/1.5049770] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
When electric current flows through a molecular junction, the molecule constantly charges and discharges by tunneling electrons. These charging and discharging events occur at specific but random times and are separated by stochastic time intervals. These time intervals can be associated with the dwelling time for a charge (electron or hole) to reside on the molecule. In this paper, the statistical properties of these time intervals are studied and a general formula for their distribution is derived. The theory is based on the Markovian master equation which takes into account transitions between the vibrational states of charged and neutral molecules in the junction. Two quantum jump operators are identified from the Liouvillian of the master equation-one corresponds to charging of the molecule and the other discharges the molecule back to the neutral state. The quantum jump operators define the conditional probability that given that the molecule was charged by a tunneling electron at time t, the molecule becomes neutral at a later time t + τ discharging the electron to the drain electrode. Statistical properties of these time intervals τ are studied with the use of this distribution.
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Affiliation(s)
- Daniel S Kosov
- College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
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23
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Pinsolle E, Houle S, Lupien C, Reulet B. Non-Gaussian Current Fluctuations in a Short Diffusive Conductor. PHYSICAL REVIEW LETTERS 2018; 121:027702. [PMID: 30085754 DOI: 10.1103/physrevlett.121.027702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Indexed: 06/08/2023]
Abstract
We report the measurement of the third moment of current fluctuations in a short metallic wire at low temperature. The data are deduced from the statistics of voltage fluctuations across the conductor using a careful determination of environmental contributions. Our results at low bias agree very well with theoretical predictions for coherent transport with no fitting parameter. By increasing the bias voltage we explore the crossover from elastic to inelastic transport.
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Affiliation(s)
- Edouard Pinsolle
- Institut Quantique, Département de Physique, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Samuel Houle
- Institut Quantique, Département de Physique, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Christian Lupien
- Institut Quantique, Département de Physique, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
| | - Bertrand Reulet
- Institut Quantique, Département de Physique, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada
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24
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Ashida Y, Ueda M. Full-Counting Many-Particle Dynamics: Nonlocal and Chiral Propagation of Correlations. PHYSICAL REVIEW LETTERS 2018; 120:185301. [PMID: 29775368 DOI: 10.1103/physrevlett.120.185301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Indexed: 06/08/2023]
Abstract
The ability to measure single quanta allows the complete characterization of small quantum systems known as full-counting statistics. Quantum gas microscopy enables one to observe many-body systems at the single-atom precision. We extend the idea of full-counting statistics to nonequilibrium open many-particle dynamics and apply it to discuss the quench dynamics. By way of illustration, we consider an exactly solvable model to demonstrate the emergence of unique phenomena such as nonlocal and chiral propagation of correlations, leading to a concomitant oscillatory entanglement growth. We find that correlations can propagate beyond the conventional maximal speed, known as the Lieb-Robinson bound, at the cost of probabilistic nature of quantum measurement. These features become most prominent at the real-to-complex spectrum transition point of an underlying parity-time-symmetric effective non-Hermitian Hamiltonian. A possible experimental situation with quantum gas microscopy is discussed.
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Affiliation(s)
- Yuto Ashida
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masahito Ueda
- Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
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25
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Ptaszyński K. First-passage times in renewal and nonrenewal systems. Phys Rev E 2018; 97:012127. [PMID: 29448475 DOI: 10.1103/physreve.97.012127] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Indexed: 11/07/2022]
Abstract
Fluctuations in stochastic systems are usually characterized by full counting statistics, which analyzes the distribution of the number of events taking place in the fixed time interval. In an alternative approach, the distribution of the first-passage times, i.e., the time delays after which the counting variable reaches a certain threshold value, is studied. This paper presents the approach to calculate the first-passage time distribution in systems in which the analyzed current is associated with an arbitrary set of transitions within the Markovian network. Using this approach, it is shown that when the subsequent first-passage times are uncorrelated, there exist strict relations between the cumulants of the full counting statistics and the first-passage time distribution. On the other hand, when the correlations of the first-passage times are present, their distribution may provide additional information about the internal dynamics of the system in comparison to the full counting statistics; for example, it may reveal the switching between different dynamical states of the system. Additionally, I show that breaking of the fluctuation theorem for first-passage times may reveal the multicyclic nature of the Markovian network.
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Affiliation(s)
- Krzysztof Ptaszyński
- Institute of Molecular Physics, Polish Academy of Sciences, ul. M. Smoluchowskiego 17, 60-179 Poznań, Poland
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26
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Xue HB, Liu XP, Chen B. Probing the internal energy structure of a serially coupled double quantum dot system with Rashba spin-orbit coupling through finite-frequency shot noise. AIP ADVANCES 2018; 8. [DOI: 10.1063/1.5004223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The finite-frequency shot noise of electron transport through a serially coupled double quantum dot system with Rashba spin-orbit coupling is studied based on an effective particle-number-resolved quantum master equation. We demonstrate that the finite-frequency shot noise displays an obvious dip, and the dip position, which is independent of the spin polarizations of the source and drain electrodes, is determined by the energy difference between the coherent singly-occupied eigenstates of the quantum dot system. These results suggest that the dip position of the finite-frequency shot noise can be used to quantitatively extract the information about the energy difference between the coherent singly-occupied eigenstates and the magnitude of Rashba spin-orbit coupling. The predicted properties of the finite-frequency shot noise are of particular interest for understanding of the internal dynamics of the coupled quantum dot systems.
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Affiliation(s)
- Hai-Bin Xue
- College of Physics and Optoelectronics, Taiyuan University of Technology , Taiyuan 030024, China
| | - Xu-Ping Liu
- College of Physics and Optoelectronics, Taiyuan University of Technology , Taiyuan 030024, China
| | - Bin Chen
- College of Physics and Optoelectronics, Taiyuan University of Technology , Taiyuan 030024, China
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27
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Contreras-Pulido LD, Bruderer M. Coherent and incoherent charge transport in linear triple quantum dots. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:185301. [PMID: 28294106 DOI: 10.1088/1361-648x/aa66d0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
One of the fundamental questions in quantum transport is how charge transfer through complex nanostructures is influenced by quantum coherence. We address this issue for linear triple quantum dots by comparing a Lindblad density matrix description with a Pauli rate equation approach and analyze the corresponding zero-frequency counting statistics of charge transfer. The impact of decaying coherences of the density matrix due to dephasing is also studied. Our findings reveal that the sensitivity to coherence shown by shot noise and skewness, in particular in the limit of large coupling to the drain reservoir, can be used to unambiguously evidence coherent processes involved in charge transport across triple quantum dots. Our analytical results are obtained by using the characteristic polynomial approach to full counting statistics.
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Affiliation(s)
- L D Contreras-Pulido
- Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, 01000 México D. F., Mexico
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28
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Wagner T, Strasberg P, Bayer JC, Rugeramigabo EP, Brandes T, Haug RJ. Strong suppression of shot noise in a feedback-controlled single-electron transistor. NATURE NANOTECHNOLOGY 2017; 12:218-222. [PMID: 27819692 DOI: 10.1038/nnano.2016.225] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 09/19/2016] [Indexed: 06/06/2023]
Abstract
Feedback control of quantum mechanical systems is rapidly attracting attention not only due to fundamental questions about quantum measurements, but also because of its novel applications in many fields in physics. Quantum control has been studied intensively in quantum optics but progress has recently been made in the control of solid-state qubits as well. In quantum transport only a few active and passive feedback experiments have been realized on the level of single electrons, although theoretical proposals exist. Here we demonstrate the suppression of shot noise in a single-electron transistor using an exclusively electronic closed-loop feedback to monitor and adjust the counting statistics. With increasing feedback response we observe a stronger suppression and faster freezing of charge current fluctuations. Our technique is analogous to the generation of squeezed light with in-loop photodetection as used in quantum optics. Sub-Poisson single-electron sources will pave the way for high-precision measurements in quantum transport similar to optical or optomechanical equivalents.
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Affiliation(s)
- Timo Wagner
- Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hannover, Germany
| | - Philipp Strasberg
- Institut für Theoretische Physik, Hardenbergstr. 36, TU Berlin, D-10623 Berlin, Germany
| | - Johannes C Bayer
- Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hannover, Germany
| | - Eddy P Rugeramigabo
- Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hannover, Germany
| | - Tobias Brandes
- Institut für Theoretische Physik, Hardenbergstr. 36, TU Berlin, D-10623 Berlin, Germany
| | - Rolf J Haug
- Institut für Festkörperphysik, Leibniz Universität Hannover, D-30167 Hannover, Germany
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29
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Dasenbrook D, Flindt C. Dynamical Scheme for Interferometric Measurements of Full-Counting Statistics. PHYSICAL REVIEW LETTERS 2016; 117:146801. [PMID: 27740844 DOI: 10.1103/physrevlett.117.146801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Indexed: 06/06/2023]
Abstract
We propose a dynamical scheme for measuring the full-counting statistics in a mesoscopic conductor using an electronic Mach-Zehnder interferometer. The conductor couples capacitively to one arm of the interferometer and causes a phase shift which is proportional to the number of transferred charges. Importantly, the full-counting statistics can be obtained from average current measurements at the outputs of the interferometer. The counting field can be controlled by varying the time delay between two separate voltage signals applied to the conductor and the interferometer, respectively. As a specific application, we consider measuring the entanglement entropy generated by partitioning electrons on a quantum point contact. Our scheme is robust against moderate environmental dephasing and may be realized thanks to recent advances in gigahertz quantum electronics.
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Affiliation(s)
- David Dasenbrook
- Département de Physique Théorique, Université de Genève, 1211 Genève, Switzerland
| | - Christian Flindt
- Department of Applied Physics, Aalto University, 00076 Aalto, Finland
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30
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Belousov R, Cohen EGD, Rondoni L. Langevin equation for systems with a preferred spatial direction. Phys Rev E 2016; 94:032127. [PMID: 27739763 DOI: 10.1103/physreve.94.032127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Indexed: 06/06/2023]
Abstract
In this paper, we generalize the theory of Brownian motion and the Onsager-Machlup theory of fluctuations for spatially symmetric systems to equilibrium and nonequilibrium steady-state systems with a preferred spatial direction, due to an external force. To do this, we extend the Langevin equation to include a bias, which is introduced by an external force and alters the Gaussian structure of the system's fluctuations. In addition, by solving this extended equation, we provide a physical interpretation for the statistical properties of the fluctuations in these systems. Connections of the extended Langevin equation with the theory of active Brownian motion are discussed as well.
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Affiliation(s)
- Roman Belousov
- The Rockefeller University, New York, New York 10065, USA
| | - E G D Cohen
- The Rockefeller University, New York, New York 10065, USA
- Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA
| | - Lamberto Rondoni
- Dipartimento di Scienze Matematiche and Graphene@Polito Lab Politecnico di Torino - Corso Duca degli Abruzzi 24, 10125, Torino, Italy
- INFN, Sezione di Torino - Via P. Giuria 1, 10125, Torino, Italy
- Kavli Institute for Theoretical Physics China, Chinese Academy of Sciences, Beijing 100190, China
- Malaysia Italy Centre of Excellence for Mathematical Sciences, University Putra Malaysia, 43400 Serdang, Selangor, Malaysia
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31
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Kurzmann A, Merkel B, Labud PA, Ludwig A, Wieck AD, Lorke A, Geller M. Optical Blocking of Electron Tunneling into a Single Self-Assembled Quantum Dot. PHYSICAL REVIEW LETTERS 2016; 117:017401. [PMID: 27419589 DOI: 10.1103/physrevlett.117.017401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Indexed: 06/06/2023]
Abstract
Time-resolved resonance fluorescence (RF) is used to analyze electron tunneling between a single self-assembled quantum dot (QD) and an electron reservoir. In equilibrium, the RF intensity reflects the average electron occupation of the QD and exhibits a gate voltage dependence that is given by the Fermi distribution in the reservoir. In the time-resolved signal, however, we find that the relaxation rate for electron tunneling is, surprisingly, independent of the occupation in the charge reservoir-in contrast to results from all-electrical transport measurements. Using a master equation approach, which includes both the electron tunneling and the optical excitation or recombination, we are able to explain the experimental data by optical blocking, which also reduces the electron tunneling rate when the QD is occupied by an exciton.
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Affiliation(s)
- A Kurzmann
- Fakultät für Physik and CENIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany
| | - B Merkel
- Fakultät für Physik and CENIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany
| | - P A Labud
- Chair of Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - A Ludwig
- Chair of Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - A D Wieck
- Chair of Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - A Lorke
- Fakultät für Physik and CENIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany
| | - M Geller
- Fakultät für Physik and CENIDE, Universität Duisburg-Essen, Lotharstraße 1, Duisburg 47048, Germany
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32
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Droste S, Governale M. Finite-time full counting statistics and factorial cumulants for transport through a quantum dot with normal and superconducting leads. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:145302. [PMID: 26963047 DOI: 10.1088/0953-8984/28/14/145302] [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
We study the finite-time full counting statistics for subgap transport through a single-level quantum dot tunnel-coupled to one normal and one superconducting lead. In particular, we determine the factorial and the ordinary cumulants both for finite times and in the long-time limit. We find that the factorial cumulants violate the sign criterion, indicating a non-binomial distribution, even in absence of Coulomb repulsion due to the presence of superconducting correlations. At short times the cumulants exhibit oscillations which are a signature of the coherent transfer of Cooper pairs between the dot and the superconductor.
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Affiliation(s)
- Stephanie Droste
- School of Chemical and Physical Sciences and Mac Diarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand
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33
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Belousov R, Cohen EGD, Wong CS, Goree JA, Feng Y. Skewness of steady-state current fluctuations in nonequilibrium systems. Phys Rev E 2016; 93:042125. [PMID: 27176272 DOI: 10.1103/physreve.93.042125] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Indexed: 06/05/2023]
Abstract
A skewness of the probability for instantaneous current fluctuations, in a nonequilibrium steady state, is observed experimentally in a dusty plasma. This skewness is attributed to the spatial asymmetry, which is imminent to the nonequilibrium systems due to the external hydrodynamic gradient. Using the modern framework of the large deviation theory, we extend the Onsager-Machlup ansatz for equilibrium fluctuations to systems with a preferred spatial direction, and provide a modulated Gaussian probability distribution, which is tested by simulations. This probability distribution is also of potential interest for other statistical disciplines. Connections with the principles of statistical mechanics, due to Boltzmann and Gibbs, are discussed as well.
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Affiliation(s)
| | - E G D Cohen
- The Rockefeller University, New York 10065, USA
- Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA
| | - Chun-Shang Wong
- Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA
| | - John A Goree
- Department of Physics and Astronomy, The University of Iowa, Iowa City, Iowa 52242, USA
| | - Yan Feng
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, College of Physics, Optoelectronics and Energy, Soochow University, Suzhou 215006, China
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34
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Agarwalla BK, Segal D. Reconciling perturbative approaches in phonon-assisted transport junctions. J Chem Phys 2016; 144:074102. [PMID: 26896971 DOI: 10.1063/1.4941582] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present consistent results for molecular conduction using two central-complementary approaches: the non-equilibrium Green's function technique and the quantum master equation method. Our model describes electronic conduction in a donor-acceptor junction in which electron transfer is coupled to nuclear motion, modeled by a harmonic vibrational mode. This primary mode is further coupled to secondary phonon modes, a thermal bath. Assuming weak electron-phonon coupling but an arbitrary large molecule-metal hybridization, we compute several non-equilibrium transport quantities: the mean phonon number of the primary mode, charge current statistics. We further present scaling relations for the cumulants valid in the large voltage regime. Our analysis illustrates that the non-equilibrium Green's function technique and the quantum master equation method can be worked out consistently, when taking into account corresponding scattering processes.
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Affiliation(s)
- Bijay Kumar Agarwalla
- Chemical Physics Theory Group, Department of Chemistry, and Centre for Quantum Information and Quantum Control, University of Toronto, 80 Saint George St., Toronto, Ontario M5S 3H6, Canada
| | - Dvira Segal
- Chemical Physics Theory Group, Department of Chemistry, and Centre for Quantum Information and Quantum Control, University of Toronto, 80 Saint George St., Toronto, Ontario M5S 3H6, Canada
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35
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Quantum Phase Coherence in Mesoscopic Transport Devices with Two-Particle Interaction. Sci Rep 2015; 5:12873. [PMID: 26255858 PMCID: PMC4530461 DOI: 10.1038/srep12873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 07/10/2015] [Indexed: 12/02/2022] Open
Abstract
In this paper we demonstrate a new type of quantum phase coherence (QPC), which is generated by the two-body interaction. This conclusion is based on quantum master equation analysis for the full counting statistics of electron transport through two parallel quantum-dots with antiparallel magnetic fluxes in order to eliminate the Aharonov-Bohm interference of either single-particle or non-interacting two-particle wave functions. The interacting two-particle QPC is realized by the flux-dependent oscillation of the zero-frequency cumulants including the shot noise and skewness with a characteristic period. The accurately quantized peaks of cumulant spectrum may have technical applications to probe the two-body Coulomb interaction.
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36
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Li ZZ, Lam CH, You JQ. Probing Majorana bound states via counting statistics of a single electron transistor. Sci Rep 2015; 5:11416. [PMID: 26098973 PMCID: PMC4476256 DOI: 10.1038/srep11416] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 05/22/2015] [Indexed: 11/09/2022] Open
Abstract
We propose an approach for probing Majorana bound states (MBSs) in a nanowire via counting statistics of a nearby charge detector in the form of a single-electron transistor (SET). We consider the impacts on the counting statistics by both the local coupling between the detector and an adjacent MBS at one end of a nanowire and the nonlocal coupling to the MBS at the other end. We show that the Fano factor and the skewness of the SET current are minimized for a symmetric SET configuration in the absence of the MBSs or when coupled to a fermionic state. However, the minimum points of operation are shifted appreciably in the presence of the MBSs to asymmetric SET configurations with a higher tunnel rate at the drain than at the source. This feature persists even when varying the nonlocal coupling and the pairing energy between the two MBSs. We expect that these MBS-induced shifts can be measured experimentally with available technologies and can serve as important signatures of the MBSs.
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Affiliation(s)
- Zeng-Zhao Li
- Laboratory for Quantum Optics and Quantum Information, Beijing Computational Science Research Center, Beijing 100094, China.,Department of Applied Physics, Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - Chi-Hang Lam
- Department of Applied Physics, Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
| | - J Q You
- Laboratory for Quantum Optics and Quantum Information, Beijing Computational Science Research Center, Beijing 100094, China
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37
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Prance JR, Van Bael BJ, Simmons CB, Savage DE, Lagally MG, Friesen M, Coppersmith SN, Eriksson MA. Identifying single electron charge sensor events using wavelet edge detection. NANOTECHNOLOGY 2015; 26:215201. [PMID: 25930073 DOI: 10.1088/0957-4484/26/21/215201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The operation of solid-state qubits often relies on single-shot readout using a nanoelectronic charge sensor, and the detection of events in a noisy sensor signal is crucial for high fidelity readout of such qubits. The most common detection scheme, comparing the signal to a threshold value, is accurate at low noise levels but is not robust to low-frequency noise and signal drift. We describe an alternative method for identifying charge sensor events using wavelet edge detection. The technique is convenient to use and we show that, with realistic signals and a single tunable parameter, wavelet detection can outperform thresholding and is significantly more tolerant to 1/f and low-frequency noise.
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Affiliation(s)
- J R Prance
- University of Wisconsin-Madison, Wisconsin 53706, USA. Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK
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38
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Brange F, Malkoc O, Samuelsson P. Subdecoherence time generation and detection of orbital entanglement in quantum dots. PHYSICAL REVIEW LETTERS 2015; 114:176803. [PMID: 25978249 DOI: 10.1103/physrevlett.114.176803] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Indexed: 06/04/2023]
Abstract
Recent experiments have demonstrated subdecoherence time control of individual single-electron orbital qubits. Here we propose a quantum-dot-based scheme for generation and detection of pairs of orbitally entangled electrons on a time scale much shorter than the decoherence time. The electrons are entangled, via two-particle interference, and transferred to the detectors during a single cotunneling event, making the scheme insensitive to charge noise. For sufficiently long detector dot lifetimes, cross-correlation detection of the dot charges can be performed with real-time counting techniques, providing for an unambiguous short-time Bell inequality test of orbital entanglement.
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Affiliation(s)
- F Brange
- Department of Physics, Lund University, Box 118, SE-221 00 Lund, Sweden
| | - O Malkoc
- Department of Physics, Lund University, Box 118, SE-221 00 Lund, Sweden
| | - P Samuelsson
- Department of Physics, Lund University, Box 118, SE-221 00 Lund, Sweden
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39
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Ferrari AC, Bonaccorso F, Fal'ko V, Novoselov KS, Roche S, Bøggild P, Borini S, Koppens FHL, Palermo V, Pugno N, Garrido JA, Sordan R, Bianco A, Ballerini L, Prato M, Lidorikis E, Kivioja J, Marinelli C, Ryhänen T, Morpurgo A, Coleman JN, Nicolosi V, Colombo L, Fert A, Garcia-Hernandez M, Bachtold A, Schneider GF, Guinea F, Dekker C, Barbone M, Sun Z, Galiotis C, Grigorenko AN, Konstantatos G, Kis A, Katsnelson M, Vandersypen L, Loiseau A, Morandi V, Neumaier D, Treossi E, Pellegrini V, Polini M, Tredicucci A, Williams GM, Hong BH, Ahn JH, Kim JM, Zirath H, van Wees BJ, van der Zant H, Occhipinti L, Di Matteo A, Kinloch IA, Seyller T, Quesnel E, Feng X, Teo K, Rupesinghe N, Hakonen P, Neil SRT, Tannock Q, Löfwander T, Kinaret J. Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems. NANOSCALE 2015; 7:4598-810. [PMID: 25707682 DOI: 10.1039/c4nr01600a] [Citation(s) in RCA: 991] [Impact Index Per Article: 110.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries. We also define an extensive list of acronyms in an effort to standardize the nomenclature in this emerging field.
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Affiliation(s)
- Andrea C Ferrari
- Cambridge Graphene Centre, University of Cambridge, Cambridge, CB3 0FA, UK.
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40
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Xue HB, Jiao HJ, Liang JQ, Liu WM. Non-Markovian full counting statistics in quantum dot molecules. Sci Rep 2015; 5:8978. [PMID: 25752245 PMCID: PMC4354005 DOI: 10.1038/srep08978] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 02/12/2015] [Indexed: 11/19/2022] Open
Abstract
Full counting statistics of electron transport is a powerful diagnostic tool for probing the nature of quantum transport beyond what is obtainable from the average current or conductance measurement alone. In particular, the non-Markovian dynamics of quantum dot molecule plays an important role in the nonequilibrium electron tunneling processes. It is thus necessary to understand the non-Markovian full counting statistics in a quantum dot molecule. Here we study the non-Markovian full counting statistics in two typical quantum dot molecules, namely, serially coupled and side-coupled double quantum dots with high quantum coherence in a certain parameter regime. We demonstrate that the non-Markovian effect manifests itself through the quantum coherence of the quantum dot molecule system, and has a significant impact on the full counting statistics in the high quantum-coherent quantum dot molecule system, which depends on the coupling of the quantum dot molecule system with the source and drain electrodes. The results indicated that the influence of the non-Markovian effect on the full counting statistics of electron transport, which should be considered in a high quantum-coherent quantum dot molecule system, can provide a better understanding of electron transport through quantum dot molecules.
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Affiliation(s)
- Hai-Bin Xue
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
| | - Hu-Jun Jiao
- Department of Physics, Shanxi University, Taiyuan 030006, China
| | - Jiu-Qing Liang
- Institute of Theoretical Physics, Shanxi University, Taiyuan 030006, China
| | - Wu-Ming Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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41
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Sothmann B, Sánchez R, Jordan AN. Thermoelectric energy harvesting with quantum dots. NANOTECHNOLOGY 2015; 26:032001. [PMID: 25549281 DOI: 10.1088/0957-4484/26/3/032001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We review recent theoretical work on thermoelectric energy harvesting in multi-terminal quantum-dot setups. We first discuss several examples of nanoscale heat engines based on Coulomb-coupled conductors. In particular, we focus on quantum dots in the Coulomb-blockade regime, chaotic cavities and resonant tunneling through quantum dots and wells. We then turn toward quantum-dot heat engines that are driven by bosonic degrees of freedom such as phonons, magnons and microwave photons. These systems provide interesting connections to spin caloritronics and circuit quantum electrodynamics.
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Affiliation(s)
- Björn Sothmann
- Département de Physique Théorique, Université de Genève, CH-1211 Genève 4, Switzerland
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42
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Abstract
We report the observation of thermal noise in the motion of single electrons in an ultimately small dynamic random access memory (DRAM). The nanometer-scale transistors that compose the DRAM resolve the thermal noise in single-electron motion. A complete set of fundamental tests conducted on this single-electron thermal noise shows that the noise perfectly follows all the aspects predicted by statistical mechanics, which include the occupation probability, the law of equipartition, a detailed balance, and the law of kT/C. In addition, the counting statistics on the directional motion (i.e., the current) of the single-electron thermal noise indicate that the individual electron motion follows the Poisson process, as it does in shot noise.
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43
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Li J, Yu T, Lin HQ, You JQ. Probing the non-locality of Majorana fermions via quantum correlations. Sci Rep 2014; 4:4930. [PMID: 24816484 PMCID: PMC4017219 DOI: 10.1038/srep04930] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 04/23/2014] [Indexed: 11/27/2022] Open
Abstract
Majorana fermions (MFs) are exotic particles that are their own anti-particles. Recently, the search for the MFs occurring as quasi-particle excitations in solid-state systems has attracted widespread interest, because of their fundamental importance in fundamental physics and potential applications in topological quantum computation based on solid-state devices. Here we study the quantum correlations between two spatially separate quantum dots induced by a pair of MFs emerging at the two ends of a semiconductor nanowire, in order to develop a new method for probing the MFs. We find that without the tunnel coupling between these paired MFs, quantum entanglement cannot be induced from an unentangled (i.e., product) state, but quantum discord is observed due to the intrinsic nonlocal correlations of the paired MFs. This finding reveals that quantum discord can indeed demonstrate the intrinsic non-locality of the MFs formed in the nanowire. Also, quantum discord can be employed to discriminate the MFs from the regular fermions. Furthermore, we propose an experimental setup to measure the onset of quantum discord due to the nonlocal correlations. Our approach provides a new, and experimentally accessible, method to study the Majorana bound states by probing their intrinsic non-locality signature.
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Affiliation(s)
- Jun Li
- 1] Beijing Computational Science Research Center, Beijing 100084, China [2] College of Physics and Electronic Engineering, Dezhou University, Dezhou 253023, China
| | - Ting Yu
- Center for Controlled Quantum Systems and Department of Physics and Engineering Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
| | - Hai-Qing Lin
- Beijing Computational Science Research Center, Beijing 100084, China
| | - J Q You
- Beijing Computational Science Research Center, Beijing 100084, China
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44
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Maisi VF, Kambly D, Flindt C, Pekola JP. Full counting statistics of Andreev tunneling. PHYSICAL REVIEW LETTERS 2014; 112:036801. [PMID: 24484157 DOI: 10.1103/physrevlett.112.036801] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Indexed: 06/03/2023]
Abstract
We employ a single-charge counting technique to measure the full counting statistics of Andreev events in which Cooper pairs are either produced from electrons that are reflected as holes at a superconductor-normal-metal interface or annihilated in the reverse process. The full counting statistics consists of quiet periods with no Andreev processes, interrupted by the tunneling of a single electron that triggers an avalanche of Andreev events giving rise to strongly super-Poissonian distributions.
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Affiliation(s)
- Ville F Maisi
- Low Temperature Laboratory (OVLL), Aalto University School of Science, P.O. Box 13500, 00076 Aalto, Finland and Centre for Metrology and Accreditation (MIKES), P.O. Box 9, 02151 Espoo, Finland
| | - Dania Kambly
- Département de Physique Théorique, Université de Genève, 1211 Genève, Switzerland
| | - Christian Flindt
- Département de Physique Théorique, Université de Genève, 1211 Genève, Switzerland
| | - Jukka P Pekola
- Low Temperature Laboratory (OVLL), Aalto University School of Science, P.O. Box 13500, 00076 Aalto, Finland
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45
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Mordovina U, Emary C. Full-counting statistics of random transition-rate matrices. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:062148. [PMID: 24483426 DOI: 10.1103/physreve.88.062148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Indexed: 06/03/2023]
Abstract
We study the full-counting statistics of current of large open systems through the application of random-matrix theory to transition-rate matrices. We develop a method for calculating the ensemble-averaged current-cumulant generating functions based on an expansion in terms of the inverse system size. We investigate how different symmetry properties and different counting schemes affect the results.
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Affiliation(s)
- Uliana Mordovina
- Institut für Theoretische Physik, Hardenbergstrasse 36, TU Berlin, D-10623 Berlin, Germany
| | - Clive Emary
- Department of Physics and Mathematics, University of Hull, Kingston-upon-Hull, HU6 7RX, United Kingdom
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46
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Abstract
We discuss graphene nanoribbon-based charge sensors and focus on their functionality in the presence of external magnetic fields and high frequency pulses applied to a nearby gate electrode. The charge detectors work well with in-plane magnetic fields of up to 7 T and pulse frequencies of up to 20 MHz. By analyzing the step height in the charge detector's current at individual charging events in a nearby quantum dot, we determine the ideal operation conditions with respect to the applied charge detector bias. Average charge sensitivities of 1.3 × 10(-3)e Hz(-1/2) can be achieved. Additionally, we investigate the back action of the charge detector current on the quantum transport through a nearby quantum dot. By varying the charge detector bias from 0 to 4.5 mV, we can increase the Coulomb peak currents measured at the quantum dot by a factor of around 400. Furthermore, we can completely lift the Coulomb blockade in the quantum dot.
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Affiliation(s)
- C Neumann
- JARA-FIT and II Institute of Physics B, RWTH Aachen University, D-52074 Aachen, Germany. Peter Grünberg Institute (PGI-9), Forschungszentrum Jülich, D-52425 Jülich, Germany
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47
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Rodríguez-Pérez S, Marino R, Novaes M, Vivo P. Statistics of quantum transport in weakly nonideal chaotic cavities. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 88:052912. [PMID: 24329336 DOI: 10.1103/physreve.88.052912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Indexed: 06/03/2023]
Abstract
We consider statistics of electronic transport in chaotic cavities where time-reversal symmetry is broken and one of the leads is weakly nonideal; that is, it contains tunnel barriers characterized by tunneling probabilities Γ(i). Using symmetric function expansions and a generalized Selberg integral, we develop a systematic perturbation theory in 1-Γ(i) valid for an arbitrary number of channels and obtain explicit formulas up to second order for the average and variance of the conductance and for the average shot noise. Higher moments of the conductance are considered to leading order.
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Affiliation(s)
- Sergio Rodríguez-Pérez
- Departamento de Física, Universidade Federal de São Carlos, São Carlos, SP, 13565-905, Brazil
| | - Ricardo Marino
- Laboratoire de Physique Théorique et Modèles Statistiques, UMR CNRS 8626, Université Paris-Sud, 91405 Orsay, France
| | - Marcel Novaes
- Departamento de Física, Universidade Federal de São Carlos, São Carlos, SP, 13565-905, Brazil
| | - Pierpaolo Vivo
- Laboratoire de Physique Théorique et Modèles Statistiques, UMR CNRS 8626, Université Paris-Sud, 91405 Orsay, France
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48
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Li ZZ, Lam CH, Yu T, You JQ. Detector-induced backaction on the counting statistics of a double quantum dot. Sci Rep 2013; 3:3026. [PMID: 24149587 PMCID: PMC3805975 DOI: 10.1038/srep03026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/04/2013] [Indexed: 12/02/2022] Open
Abstract
Full counting statistics of electron transport is of fundamental importance for a deeper understanding of the underlying physical processes in quantum transport in nanoscale devices. The backaction effect from a detector on the nanoscale devices is also essential due to its inevitable presence in experiments. Here we investigate the backaction of a charge detector in the form of a quantum point contact (QPC) on the counting statistics of a biased double quantum dot (DQD). We show that this inevitable QPC-induced backaction can have profound effects on the counting statistics under certain conditions, e.g., changing the shot noise from being sub-Poissonian to super-Poissonian, and changing the skewness from being positive to negative. Also, we show that both Fano factor and skewness can be either enhanced or suppressed by increasing the energy difference between two single-dot levels of the DQD under the detector-induced backaction.
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Affiliation(s)
- Zeng-Zhao Li
- Beijing Computational Science Research Center, Beijing 100084, China
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49
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Noise intensity-intensity correlations and the fourth cumulant of photo-assisted shot noise. Sci Rep 2013; 3:2869. [PMID: 24100407 PMCID: PMC3792424 DOI: 10.1038/srep02869] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/19/2013] [Indexed: 11/24/2022] Open
Abstract
We report the measurement of the fourth cumulant of current fluctuations in a tunnel junction under both dc and ac (microwave) excitation. This probes the non-Gaussian character of photo-assisted shot noise. Our measurement reveals the existence of correlations between noise power measured at two different frequencies, which corresponds to two-mode intensity correlations in optics. We observe positive correlations, i.e. photon bunching, which exist only for certain relations between the excitation frequency and the two detection frequencies, depending on the dc bias of the sample.
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50
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House MG, Xiao M, Guo G, Li H, Cao G, Rosenthal MM, Jiang H. Detection and measurement of spin-dependent dynamics in random telegraph signals. PHYSICAL REVIEW LETTERS 2013; 111:126803. [PMID: 24093289 DOI: 10.1103/physrevlett.111.126803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Indexed: 06/02/2023]
Abstract
A quantum point contact was used to observe single-electron fluctuations of a quantum dot in a GaAs heterostructure. The resulting random telegraph signals (RTS) contain statistical information about the electron spin state if the tunneling dynamics are spin dependent. We develop a statistical method to extract information about spin-dependent dynamics from RTS and use it to demonstrate that these dynamics can be studied in the thermal energy regime. The tunneling rates of each spin state are independently measured in a finite external magnetic field. We confirm previous findings of a decrease in overall tunneling rates for the spin excited state compared to the ground state as an external magnetic field is increased.
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Affiliation(s)
- M G House
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, California 90095, USA
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