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Related papers: Spin fluctuations in the 0.7-anomaly in quantum po…

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A Quantum Point Contact (QPC) causes a one-dimensional constriction on the spatial potential landscape of a two-dimensional electron system. By tuning the voltage applied on a QPC at low temperatures the resulting regular step-like electron…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 E. Schubert , J. Heyder , F. Bauer , W. Stumpf , W. Wegscheider , J. v. Delft , S. Ludwig , A. Högele

We study one-dimensional itinerant electron models with ferromagnetic coupling to investigate the origin of 0.7 anomaly in quantum point contacts. Linear conductance calculations from the quantum Monte Carlo technique for spin interactions…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 K. Aryanpour , J. E. Han

We study how the conductance of a quantum point contact is affected by spin-orbit interactions, for systems at zero temperature both with and without electron-electron interactions. In the presence of spin-orbit coupling, tuning the…

Mesoscale and Nanoscale Physics · Physics 2015-01-07 Olga Goulko , Florian Bauer , Jan Heyder , Jan von Delft

Apart from usual quantization steps on the ballistic conductance of a quasi-one-dimensional conductor, an additional plateau-like feature appears at a fraction of about 0.7 below the first conductance step in GaAs-based quantum point…

Mesoscale and Nanoscale Physics · Physics 2016-07-08 Tadeusz Figielski

Quantum point contacts (QPCs) and quantum dots (QDs), two elementary building blocks of semiconducting nanodevices, both exhibit famously anomalous conductance features: the 0.7-anomaly in the former case, the Kondo effect in the latter.…

Strongly Correlated Electrons · Physics 2015-11-11 Jan Heyder , Florian Bauer , Enrico Schubert , David Borowsky , Dieter Schuh , Werner Wegscheider , Jan von Delft , Stefan Ludwig

We consider a mechanism of spin decay for an electron spin in a quantum dot due to coupling to a nearby quantum point contact (QPC) with and without an applied bias voltage. The coupling of spin to charge is induced by the spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Massoud Borhani , Vitaly N. Golovach , Daniel Loss

The spin degeneracy of the lowest subband that carries one-dimensional electron transport in quantum point contacts appears to be spontaneously lifted in zero magnetic field due to a phenomenon that is known as the 0.7 anomaly. We measured…

Mesoscale and Nanoscale Physics · Physics 2012-08-23 E. J. Koop , A. I. Lerescu , J. Liu , B. J. van Wees , D. Reuter , A. D. Wieck , C. H. van der Wal

Quantum point contacts (QPCs) have shown promise as nanoscale spin-selective components for spintronic applications and are of fundamental interest in the study of electron many-body effects such as the 0.7 x 2e^2/h anomaly. We report on…

Mesoscale and Nanoscale Physics · Physics 2012-08-24 A. M. Burke , O. Klochan , I. Farrer , D. A. Ritchie , A. R. Hamilton , A. P. Micolich

We study influence of electron-electron interaction on statistics of Coulomb blockade peak spacings in disordered quantum dots. It is shown that the interaction combined with fluctuations of eigenfunctions of the Fermi sea, enhances the…

Mesoscale and Nanoscale Physics · Physics 2009-10-28 Ya. M. Blanter , A. D. Mirlin , B. A. Muzykantskii

The inclusion of charging and spin-exchange interactions within the Universal Hamiltonian description of quantum dots is challenging as it leads to a non-Abelian action. Here we present an exact analytical solution of the probem, in…

Mesoscale and Nanoscale Physics · Physics 2012-04-13 I. S. Burmistrov , Yuval Gefen , M. N. Kiselev

Features below the first conductance plateau in ballistic quantum point contacts (QPCs) are often ascribed to electron interaction and spin effects within the single mode limit. In QPCs with a highly asymmetric geometry, we observe sharp…

Mesoscale and Nanoscale Physics · Physics 2019-04-01 Phillip M Wu , Peng Li , Albert M Chang

We measure the transmission phase of a quantum point contact (QPC) at a low carrier density in which electron interaction is expected to play an important role and anomalous behaviors are observed. In the first conductance plateau, the…

Mesoscale and Nanoscale Physics · Physics 2013-07-01 Toshiyuki Kobayashi , Shoei Tsuruta , Satoshi Sasaki , Hiroyuki Tamura , Tatsushi Akazaki

We explore the static longitudinal and dynamic transverse spin susceptibilities in quantum dots and nanoparticles within the framework of the Hamiltonian that extends the universal Hamiltonian to the case of uniaxial anisotropic exchange.…

Mesoscale and Nanoscale Physics · Physics 2015-07-30 A. U. Sharafutdinov , D. S. Lyubshin , I. S. Burmistrov

We study electronic transport through a quantum point contact, where the interaction between the electrons is approximated by a contact potential. Our numerical approach is based on the non-equilibrium Green function technique which is…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Andreas Lassl , Peter Schlagheck , Klaus Richter

Overdoped cuprate superconductors are strange metals above their superconducting transition temperature. In such materials, the electrical resistivity has a strong linear dependence on temperature ($T$) and electrical current is not carried…

The conductance of a quantum point contact (QPC) shows several features that result from many-body electron interactions. The spin degeneracy in zero magnetic field appears to be spontaneously lifted due to the so-called 0.7 anomaly.…

Mesoscale and Nanoscale Physics · Physics 2007-10-02 E. J. Koop , A. I. Lerescu , J. Liu , B. J. van Wees , D. Reuter , A. D. Wieck , C. H. van der Wal

The phenomenology of the "0.7 anomaly" in quantum point contacts is fully explained in terms of a quasi-localized state, which forms as the point contact opens up. Detailed numerical calculations within spin-density functional theory indeed…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Yigal Meir

We study electron spin dynamics whose movement is restricted to the lowest one dimensional subband channel ($G \le 2e^2/h $), through nuclear spin relaxation rate measurement ($1/T_1$). We observe an unusual double-peak structure in the…

Mesoscale and Nanoscale Physics · Physics 2024-11-27 M. H. Fauzi , M. Takahashi , T. Aono , K. Hashimoto , Y. Hirayama

It is proposed that the 50-70 meV dispersion anomaly (kink) in electron-doped cuprates revealed by recent angle-resolved photoemission spectroscopy experiments is caused by coupling with the spin fluctuation. We elaborate that the kink…

Superconductivity · Physics 2009-04-11 Tao Zhou , C. S. Ting

The origin of the 0.7-conductance anomaly in quantum point contacts (QPCs) has been a subject of lively discussions since its discovery more than 10 years ago. In a recent letter, based on spin density functional theory (DFT), Rejec and…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 S. Ihnatsenka , I. V. Zozoulenko
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