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Related papers: Observation of Quantum Asymmetry in an Aharonov-Bo…

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We have investigated the Aharonov-Bohm effect in mesoscopic semiconductor GaAs/GaAlAs rings in low magnetic fields. The oscillatory magnetoconductance of these systems is systematically studied as a function of electron density. We observe…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. E. Hansen , S. Pedersen , A. Kristensen , C. B. Sorensen , P. E. Lindelof

The Aharonov-Bohm effect is investigated in two-dimensional, single-terminal quantum rings in magnetic fields by using time-dependent density-functional theory. We find multiple transport loops leading to the oscillation periods of h/(en),…

Strongly Correlated Electrons · Physics 2010-06-22 V. Kotimaki , E. Rasanen

The Aharonov-Bohm (AB) interference patterns in ring-shaped conductors are usually dominated by random features. The amplitude of the oscillations is random from sample to sample and from point to point on the magnetic field axis owing to…

Condensed Matter · Physics 2009-10-22 J. Liu , W. X. Gao , K. Ismail , K. Y. Lee , J. M. Hong , S. Washburn

With an atomic force microscope a ring geometry with self-aligned in-plane gates was directly written into a GaAs/AlGaAs-heterostructure. Transport measurements in the open regime show only one transmitting mode and Aharonov-Bohm…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 U. F. Keyser , S. Borck , R. J. Haug , W. Wegscheider , M. Bichler , G. Abstreiter

We report a study of the Aharonov-Bohm effect, the oscillations of the resistance of a mesoscopic ring as a function of a perpendicular magnetic field, in a GaAs two-dimensional hole system with a strong spin-orbit interaction. The Fourier…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Jeng-Bang Yau , E. P. De Poortere , M. Shayegan

We take a negative delta function impurity in one arm of a quasi one dimensional Aharonov-Bohm ring and demonstrate abrupt phase changes across a quasi bound state of the negative delta function potential. We give a new mechanism for…

Mesoscale and Nanoscale Physics · Physics 2008-02-03 P. Singha Deo

Aharonov-Bohm oscillations are studied in the magnetoconductance of a micron-sized open quantum ring coupled capacitively to a Coulomb-blockaded quantum dot. As the plunger gate of the dot is modulated and tuned through a conductance…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 L. Meier , A. Fuhrer , T. Ihn , K. Ensslin , W. Wegscheider , M. Bichler

We investigate theoretically the collective charge density wave motion through an ensemble of small disordered Aharonov-Bohm rings. It is shown that the magnetic flux modulates the threshold field and the magnetoresistance with a half flux…

Condensed Matter · Physics 2009-10-30 M. I. Visscher , B. Rejaei

We have explored phase coherent transport of holes in two p-type GaAs quantum rings with orbital radii 420 nm and 160 nm fabricated with AFM oxidation lithography. Highly visible Aharonov-Bohm (AB) oscillations are measured in both rings,…

Mesoscale and Nanoscale Physics · Physics 2008-03-30 Boris Grbic , Renaud Leturcq , Thomas Ihn , Klaus Ensslin , Dirk Reuter , Andreas D. Wieck

We have measured the flux dependence of both real and imaginary conductance of $GaAs/GaAlAs$ isolated mesoscopic rings at 310 MHz. The rings are coupled to a highly sensitive electromagnetic superconducting micro-resonator and lead to a…

Condensed Matter · Physics 2009-10-28 Bertrand Reulet , Michel Ramin , Helene Bouchiat , Dominique Mailly

The Aharonov-Bohm effect is measured in a four-terminal open ring geometry based on a Ga[Al]As heterostructure. Two quantum dots are embedded in the structure, one in each of the two interfering paths. The number of electrons in the two…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Sigrist , A. Fuhrer , T. Ihn , K. Ensslin , S. E. Ulloa , W. Wegscheider , M. Bichler

A new diagrammatic method, which is a reformulation of Berezinskii's technique, is constructed to study the density of electronic states $\rho(\epsilon,\phi)$ of a one-channel weakly disordered ring, threaded by an external magnetic flux.…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 E. P. Nakhmedov , H. Feldmann , R. Oppermann

We measured Aharonov-Bohm resistance oscillations in a shallow two-dimensional GaAs hole ring structure, defined by local anodic surface oxidation. The amplitude of the oscillations is about 10% of the ring resistance, the strongest seen in…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 B. Habib , E. Tutuc , M. Shayegan

We investigate experimentally transport through ring-shaped devices etched in graphene and observe clear Aharonov-Bohm conductance oscillations. The temperature dependence of the oscillation amplitude indicates that below 1 K the phase…

We investigate ballistic transport and quantum interference in a nanoscale quantum wire loop fab-ricated as a GaAs/AlGaAs field-effect heterostructure. Four-terminal measurements of current and voltage characteristics as a function of top…

Mesoscale and Nanoscale Physics · Physics 2011-11-08 S. S. Buchholz , S. F. Fischer , U. Kunze , D. Reuter , A. D. Wieck

We use spin-density-functional theory within an envelope function approach to calculate electronic states in a GaAs/InAs core-shell nanowire pierced by an axial magnetic field. Our fully 3D quantum modeling includes explicitly the…

Mesoscale and Nanoscale Physics · Physics 2015-03-31 Miquel Royo , Carlos Segarra , Andrea Bertoni , Guido Goldoni , Josep Planelles

We report on magnetoresistance transport measurements performed on a bipartite tiling of rhombus in the GaAs/GaAlAs system. We observe for the first time large amplitude $h/e$ oscillations in this network as compared to the one measured in…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Cecile Naud , Giancarlo Faini , Dominique Mailly

Signature of phase coherence on the electric and magnetic response of non connected Aharonov-Bohm rings is measured by a resonant method at 350 MHz between 20 mK and 500 mK. The rings are etched in a GaAs-AlGaAs heterojunction. Both…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 R. Deblock , Y. Noat , B. Reulet , H. Bouchiat , D. Mailly

We define a mesoscopic ring in a 2-dimensional electron gas (2DEG) interrupted by two tunnel barriers, enabling us to apply a well-defined potential difference between the two halves of the ring. The electron interference in the ring is…

Phase effects on the conductance of a double-dot system in a ring structure threaded by a magnetic flux are studied. The Aharonov-Bohm effect combined with the dot many-body charging effects determine the phases of the currents going…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 V. M. Apel , Maria A. Davidovich , G. Chiappe , E. V. Anda
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