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Related papers: Current Noise in Quantum Point Contacts

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We have measured the shot noise in a quantum point contact (QPC) fabricated by using InGaAs/InGaAsP heterostructure, whose conductance can be electrically tuned by the gate voltages. The reduced shot noise is observed when the QPC…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Yoshitaka Nishihara , Shuji Nakamura , Kensuke Kobayashi , Teruo Ono , Makoto Kohda , Junsaku Nitta

We study inelastic effects on the electronic current noise in molecular junctions, due to the coupling between transport electrons and vibrational degrees of freedom. Using a full counting statistics approach based on the generalized…

Mesoscale and Nanoscale Physics · Physics 2010-10-27 Federica Haupt , Tomas Novotny , Wolfgang Belzig

Shot noise measurements provide information on particles' charge and their correlations. We report on shot noise measurements in a ubiquitous quantum dot under a quantized magnetic field. The measured noise at the peaks of a sequence of…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 O. Zarchin , Y. C. Chung , M. Heiblum , D. Rohrlich , V. Umansky

By coupling on chip a carbon nanotube to a quantum noise detector, a superconductor-insulator-superconductor junction, via a resonant circuit, we measure the emission noise of a carbon nanotube quantum dot in the Kondo regime. The signature…

Mesoscale and Nanoscale Physics · Physics 2018-02-07 R. Delagrange , J. Basset , H. Bouchiat , R. Deblock

We describe a field-theoretic approach to calculate quantum shot noise in nanoscale conductors from first principles. Our starting point is the second-quantization field operator to calculate shot noise in terms of single quasi-particle…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Yu-Chang Chen , Massimiliano Di Ventra

We analyze the frequency-dependent noise of a current through a quantum dot which is coupled to Fermi leads and which is in the Coulomb blockade regime. We show that the asymmetric shot noise as function of frequency shows steps and becomes…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hans-Andreas Engel , Daniel Loss

We study the transport properties of two double quantum dots in a parallel arrangement at temperatures of a few Kelvin. Thereby, we show that decoherence entailed by the substrate phonons affects the shot noise. For asymmetric coupling…

Mesoscale and Nanoscale Physics · Physics 2008-01-10 Rafael Sánchez , Sigmund Kohler , Peter Hänggi , Gloria Platero

We have studied quantum wires using the Green's function technique and the density-functional theory, calculating the electronic structure and the conductance. All the numerics are implemented using the finite-element method with a…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Paula Havu , Martti Puska , Risto Nieminen , Ville Havu

Shot noise encodes additional information not directly inferable from simple electronic transport measurements. Previous measurements in atomic-scale metal junctions at cryogenic temperatures have shown suppression of the shot noise at…

Mesoscale and Nanoscale Physics · Physics 2010-03-09 P. J. Wheeler , J. N. Russom , K. Evans , N. S. King , D. Natelson

Electrical conductance measurements have limited scope in identifying Andreev edge states (AESs), which form the basis for realizing various topological excitations in quantum Hall (QH) - superconductor (SC) junctions. To unambiguously…

Current fluctuations related to the discreteness of charge passing through small constrictions are termed shot noise. This unavoidable noise provides both advantages - being a direct measurement of the transmitted particles' charge, and…

Mesoscale and Nanoscale Physics · Physics 2022-04-06 Idan Tamir , Verena Caspari , Daniela Rolf , Christian Lotze , Katharina J. Franke

Quantum shot noise probes the dynamics of charge transfers through a quantum conductor, reflecting whether quasiparticles flow across the conductor in a steady stream, or in syncopated bursts. We have performed high-sensitivity shot noise…

Current quantum noise can be pictured as a sum over transitions through which the electronic system exchanges energy with its environment. We formulate this picture and use it to show which type of current correlators are measurable, and in…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 U. Gavish , Y. Imry , Y. Levinson

We study the noise spectra of a many-level quantum dot coupled to two electron reservoirs, when interactions are taken into account only on the dot within the Hartree-Fock approximation. The dependence of the noise spectra on the…

Mesoscale and Nanoscale Physics · Physics 2015-05-30 N. Gabdank , E. A. Rothstein , O. Entin-Wohlman , A. Aharony

The shot noise of a one-dimensional wire interrupted by two barriers shows interesting features related to the interplay between Coulomb blockade effects, Luttinger correlations and discrete excitations. At small bias the Fano factor…

Strongly Correlated Electrons · Physics 2007-05-23 A. Braggio , R. Fazio , M. Sassetti

The shot noise in a quantum ring, connected to leads, is studied in the presence of electron interactions in the sequential tunneling regime. Two qualitatively different noise correlations with distinctly different behaviors are identified…

Mesoscale and Nanoscale Physics · Physics 2011-10-10 F. Cavaliere , F. Haupt , R. Fazio , M. Sassetti

We have calculated the finite-frequency current noise of a superconductor-ferromagnet quantum point contact (SF QPC). This signal is qualitatively affected by the spin-dependence of interfacial phase shifts (SDIPS) acquired by electrons…

Mesoscale and Nanoscale Physics · Physics 2009-02-23 Audrey Cottet , Benoit Doucot , Wolfgang Belzig

The current noise through a mesoscopic quantum dot is calculated and analyzed in the Fermi liquid regime of the SU(N) Kondo model. Results connect the Johnson-Nyquist noise to the shot noise for an arbitrary ratio of voltage and…

Mesoscale and Nanoscale Physics · Physics 2008-02-05 Christophe Mora , Xavier Leyronas , Nicolas Regnault

Charge detection utilizing a highly biased quantum point contact has become the most effective probe for studying few electron quantum dot circuits. Measurements on double and triple quantum dot circuits is performed to clarify a back…

Mesoscale and Nanoscale Physics · Physics 2008-05-04 D. Taubert , M. Pioro-Ladrière , D. Schröer , D. Harbusch , A. S. Sachrajda , S. Ludwig

Using non-equilibrium Green functions we calculate the spin-polarized current and shot noise in a ferromagnet--quantum-dot--ferromagnet (FM-QD-FM) system. Both parallel (P) and antiparallel (AP) magnetic configurations are considered.…

Mesoscale and Nanoscale Physics · Physics 2008-10-31 F. M. Souza , A. P. Jauho , J. C. Egues