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相关论文: Mesoscopic conductance effects in InMnAs structure…

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Quasi-ballistic semiconductor quantum wires are exposed to localized perpendicular magnetic fields, also known as magnetic barriers. Pronounced, reproducible conductance fluctuations as a function of the magnetic barrier amplitude are…

介观与纳米尺度物理 · 物理学 2009-11-13 S. Hugger , Hengyi Xu , A. Tarasov , M. Cerchez , T. Heinzel , I. V. Zozoulenko , D. Reuter , A. D. Wieck

As an exotic quantum condensed matter, the topological insulator (TI) is a bulk-insulating material with a Dirac-type conducting surface state. Such dissipationless transport of topological surface states (TSSs) is protected by the…

介观与纳米尺度物理 · 物理学 2017-10-24 Shuai Zhang , Zhaoguo Li , Fengqi Song

We study anomalous mesoscopic transport effects at the onset of the superconducting transition focusing on the observed large Nernst-Ettinghausen signal in disordered thin films. In the vicinity of the transition, as the Ginzburg-Landau…

超导电性 · 物理学 2019-05-15 Mengling Hettinger , Maxim Khodas , Alex Levchenko

Quantum interference phenomena in the conductivity of mesoscopic ferromagnets are considered, particularly with regard to the effects of geometric phases acquired by electrons propagating through regions of spatially varying magnetization…

介观与纳米尺度物理 · 物理学 2009-10-31 Yuli Lyanda-Geller , I. L. Aleiner , Paul M. Goldbart

The observation of isolated positive and negative charges, but not isolated magnetic north and south poles, is an old puzzle. Instead, evidence of effective magnetic monopoles has been found in the abstract momentum space. Apart from…

介观与纳米尺度物理 · 物理学 2010-11-19 Kjetil M. D. Hals , Anh Kiet Nguyen , Xavier Waintal , Arne Brataas

Fluctuations are important near phase transitions, where they can be difficult to describe quantitatively. Superconductivity in mesoscopic rings is particularly intriguing because the critical temperature is an oscillatory function of…

超导电性 · 物理学 2009-01-06 Nicholas C. Koshnick , Hendrik Bluhm , Martin E. Huber , Kathryn A. Moler

We evaluate a typical value of higher order cumulants (irreducible moments) of conductance fluctuations that could be extracted from magneto-conductance measurements in a single sample when an external magnetic field is swept over an…

介观与纳米尺度物理 · 物理学 2009-11-10 O. Tsyplyatyev , I. L. Aleiner , Vladimir I. Fal'ko , Igor V. Lerner

We perform electrical field effect measurements at 4 K on insulating granular aluminium thin films. When the samples size is reduced below 100 micrometers, reproducible and stable conductance fluctuations are seen as a function of the gate…

无序系统与神经网络 · 物理学 2008-09-08 J. Delahaye , T. Grenet , F. Gay

The magnetic field driven superconductor/insulator transition is studied in a large variety of $La_{2-x}Sr_xCuO_4$ thin films of various Sr dopings. Temperature dependence of the resistivity down to 4.2 or 1.5 K under high pulsed magnetic…

We calculate the fluctuation correction to the normal state conductivity in the vicinity of a quantum phase transition from a superconducting to normal state, induced by applying a magnetic field parallel to a dirty thin film or a nanowire…

超导电性 · 物理学 2007-05-23 A. V. Lopatin , N. Shah , V. M. Vinokur

Universal conductance fluctuations are usually observed in the form of aperiodic oscillations in the magnetoresistance of thin wires as a function of the magnetic field B. If such oscillations are completely random at scales exceeding…

无序系统与神经网络 · 物理学 2021-12-28 I. M. Suslov

The electrical conductivity induced near the superconducting transition by thermal fluctuations was measured in different granular aluminum films. The seemingly anomalous behavior at high reduced temperatures and magnetic fields is…

超导电性 · 物理学 2019-09-11 D. Sóñora , C. Carballeira , J. J. Ponte , F. Vidal , T. Grenet , J. Mosqueira

We develop a time dependent random matrix theory describing the influence of a time-dependent perturbation on mesoscopic conductance fluctuations in open quantum dots. The effect of external field is taken into account to all orders of…

介观与纳米尺度物理 · 物理学 2009-11-07 Maxim G. Vavilov , Igor L. Aleiner

We report the effect of the \emph{ab}-plane magnetic field $B$ up to $8\,\mathrm{T}$ on the resistivity $\rho(T)$ and fluctuation conductivity $\sigma'(T)$ in YBa$_2$Cu$_3$O$_{7-\delta}$ thin films. As expected, up to $\sim 2.5\,\mathrm{T}$…

Signatures of spin-glass freezing such as the appearance of 1/f conductance noise, the recovery of universal conductance fluctuations, aging, as well as magnetic and thermal irreversibilities are detected in mesoscopic wires of CdMnTe:I at…

介观与纳米尺度物理 · 物理学 2009-10-31 J. Jaroszynski , J. Wrobel , G. Karczewski , T. Wojtowicz , T. Dietl

We suggest an analytical theory to describe angular magnetic oscillations recently discovered in quasi-one-dimensional conductor (TMTSF)2PF6 [see Phys. Rev. B, 57, 7423 (1998)] and define the positions of the oscillation minima. The origin…

超导电性 · 物理学 2009-11-10 A. G. Lebed , M. J. Naughton

The temperature effect of quantum interference on resistivity is examined in monolayer graphene, with experimental results showing that the amplitude of the conductance fluctuation increases as temperature decreases. We find that this…

介观与纳米尺度物理 · 物理学 2017-09-07 D. Terasawa , A. Fukuda , A. Fujimoto , Y. Ohno , K. Matsumoto

Measurements of the low frequency electrical noise in the ferromagnetic semiconductor (Ga,Mn)As reveal an enhanced integrated noise at low temperature. For moderate localization, we find a 1/f normalized power spectrum density over the…

材料科学 · 物理学 2010-06-30 M. Zhu , X. Li , G. Xiang , N. Samarth

We have studied the magnetic field dependence of the temperature derivative of the resistivity, dr(H,T)/dT, of a number of Y1-xCaxBa2(Cu1-yZny)3O7-d crystalline thin films over a wide range of sample compositions. From the analysis of the…

超导电性 · 物理学 2009-11-11 S. H. Naqib , J. R. Cooper , R. S. Islam

We report a systematic experimental study of mesoscopic conductance fluctuations in superconductor/normal/superconductor (SNS) devices Nb/InAs-nanowire/Nb. These fluctuations far exceed their value in the normal state and strongly depend on…

介观与纳米尺度物理 · 物理学 2009-12-18 T. S. Jespersen , M. L. Polianski , C. B. Soerensen , K. Flensberg , J. Nygaard