共查询到20条相似文献,搜索用时 15 毫秒
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A. Yu. Mironov P. Yu. Gatilov T. I. Baturina 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(2):141-143
The low-temperature transport properties of nanoperforated superconducting TiN films have been experimentally studied. A periodic dependence of the resistance on an external magnetic field, with a period corresponding to a magnetic flux quantum per cell, is observed. An anomalous temperature dependence of the oscillation amplitude is found. The role of the effects of electron-electron interaction and localization in the physical properties of arrays of weak links, based on strongly disordered superconducting films, is discussed. 相似文献
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Kartsovnik MV Grigoriev PD Biberacher W Kushch ND Wyder P 《Physical review letters》2002,89(12):126802
Slow oscillations of the interlayer magnetoresistance observed in the layered organic metal beta-(BEDT-TTF)(2)IBr(2) are shown to originate from the slight warping of its Fermi surface rather than from independent small cyclotron orbits. Unlike the usual Shubnikov-de Haas effect, these oscillations are not affected by the temperature smearing of the Fermi distribution and can therefore become dominant at high enough temperatures. We suggest that the slow oscillations are a general feature of clean quasi-two-dimensional metals and discuss possible applications of the phenomenon. 相似文献
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A model of spin-dependent transport of electrons through a ferromagnet-insulator-ferromagnet structure is developed. It takes
into account the image forces, tunnel barrier parameters, and effective masses of an electron tunneling in the barrier and
in the ferromagnetic electrode in the free electron approximation. Calculations for an iron-aluminum oxide-iron structure
show that, with an increase in the bias voltage, the tunnel magnetoresistance decreases monotonically and then breaks into
damped oscillations caused by the interference of the electrons’ wave functions in the conduction region of the potential
barrier. The image forces increase the tunnel magnetoresistance by two or three times. 相似文献
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We have observed in potassium the spectrum of the longitudinal helicon oscillations. We have used these oscillations to measure the magnetoresistance and Hall coefficient. In addition, a low frequency method for the measurement of magnetoresistance in metals is demonstrated with experiments on single crystal potassium spheres. The magnetoresistance saturates, but its magnitude depends upon sample history. 相似文献
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Victor M. Yakovenko Benjamin K. Cooper 《Physica E: Low-dimensional Systems and Nanostructures》2006,34(1-2):128
Angular magnetoresistance oscillations (AMRO) were originally discovered in organic conductors and then found in many other layered metals. It should be possible to observe AMRO to semiconducting bilayers as well. Here we present an intuitive geometrical interpretation of AMRO as the Aharonov–Bohm interference effect, both in real and momentum spaces, for balanced and imbalanced bilayers. Applications to the experiments with bilayers in tilted magnetic fields in the metallic state are discussed. We speculate that AMRO may be also observed when each layer of the bilayer is in the composite-fermion state. 相似文献
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We studied voltage steps in the transition curve U(T) of superconducting Pb-film strips. The steps strongly depend on the thermal conductivity of the substrate and indicate the formation of phase-slip centers and hot spots. 相似文献
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We study the geometrical commensurability oscillations imposed on the resistivity of 2D electrons in a perpendicular magnetic field by a propagating surface acoustic wave (SAW). We show that, for omega相似文献
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Recent measurements of a 2D electron gas subjected to microwave radiation reveal a magnetoresistance with an oscillatory dependence on the ratio of radiation frequency to cyclotron frequency. We perform a diagrammatic calculation and find radiation-induced resistivity oscillations with the correct period and phase. Results are explained via a simple picture of current induced by photoexcited disorder-scattered electrons. The oscillations increase with radiation intensity, easily exceeding the dark resistivity and resulting in negative-resistivity minima. At high intensity, we identify additional features, likely due to multiphoton processes, which have yet to be observed experimentally. 相似文献
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Hoffman AJ Srinivasan SJ Schmidt S Spietz L Aumentado J Türeci HE Houck AA 《Physical review letters》2011,107(5):053602
Mediated photon-photon interactions are realized in a superconducting coplanar waveguide cavity coupled to a superconducting charge qubit. These nonresonant interactions blockade the transmission of photons through the cavity. This so-called dispersive photon blockade is characterized by measuring the total transmitted power while varying the energy spectrum of the photons incident on the cavity. A staircase with four distinct steps is observed and can be understood in an analogy with electron transport and the Coulomb blockade in quantum dots. This work differs from previous efforts in that the cavity-qubit excitations retain a photonic nature rather than a hybridization of qubit and photon and provides the needed tolerance to disorder for future condensed matter experiments. 相似文献
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We have used guided optical waves to locally illuminate superconducting thin lead strips and measured the critical current as a function of optical power. The measured results resemble the predictions of a simple heating model more closely than the Parker T1 model in the temperature range investigated (5.5 K to Tc) and several possible reasons for this behavior are discussed. 相似文献
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S. I. Dorozhkin 《JETP Letters》2003,77(10):577-581
For high-mobility two-dimensional electrons at a GaAs/AlGaAs heterojunction, we have studied, both experimentally and theoretically, the recently discovered giant magnetoresistance oscillations with nearly zero resistance in the oscillation minima which appear under microwave radiation. We have proposed a model based on nonequilibrium occupation of Landau levels caused by radiation which describes the oscillation picture. 相似文献
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《中国科学:物理学 力学 天文学(英文版)》2010,(7)
We prepared a series of β-FeSe samples with a nominal composition of Fe1.11Se1-xSbx(0≤x≤0.5).The X-ray diffraction,transport and magnetic measurements were performed on these samples to investigate the structure,the superconducting properties and the normal state transport and magnetic properties.Although the X-ray diffraction data suggested that Sb atoms were not incorporated into the β-FeSe phase,the transport data showed observable changes of superconductivity,normal state resistivity and magnetoresistance.This was represented by the increase in the superconducting transition temperature and the upper critical field.Also,for the samples with a low level of Sb content,a clear decrease of the normal state resistivity and a substantial increase of the residual resistance ratio were observed.Furthermore,the samples showed a significant increase of the normal state magnetoresistance that appeared not to follow the Kohler's rule.The results were discussed in the frame of reduction of excess Fe at interstitial sites of β-FeSe. 相似文献
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We have observed coherent oscillations in a multilevel quantum system, formed by a current-biased dc SQUID. These oscillations have been induced by applying resonant microwave pulses of flux. Quantum measurement is performed by a nanosecond flux pulse that projects the final state onto one of two different voltage states of the dc SQUID, which can be read out. The number of quantum states involved in the coherent oscillations increases with increasing microwave power. The dependence of the oscillation frequency on microwave power deviates strongly from the linear regime expected for a two-level system and can be very well explained by a theoretical model taking into account the anharmonicity of the multilevel system. 相似文献