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Quantum behavior of superconducting nanowires may essentially depend on the employed experimental setup. Here we investigate a setup that enables passing equilibrium supercurrent across an arbitrary segment of the wire without restricting…

Mesoscale and Nanoscale Physics · Physics 2019-08-07 Alexey Radkevich , Andrew G. Semenov , Andrei D. Zaikin

We present the magnetotransport properties of very thin (5 to 15 nm) single (Ga,Mn)As layers grown by low temperature molecular beam epitaxy. A lower (Ga,Mn)As thickness limit of 5 nm for the ferromagnetic phase and the dependence of the…

Materials Science · Physics 2009-11-07 B. S. Sorensen , J. sadowski , S. E. Andresen , P. E. Lindelof

Conductance fluctuations have been observed in macroscopic, quasi 3D PbTe wide quantum wells. A significant increase of the correlation field occurs in a temperature range from 40 mK to 1.2K. At the same time the fluctuation amplitude stays…

Materials Science · Physics 2008-02-03 J. Oswald , G. Span , A. Homer , G. Heigl , P. Ganitzer , D. K. Maude , J. C. Portal

We report on a low-temperature transport study of a single-gate, planar field-effect device made from a free-standing, wurtzite-crystalline InAs nanosheet. The nanosheet is grown via molecular beam epitaxy and the field-effect device is…

Mesoscale and Nanoscale Physics · Physics 2020-10-08 Furong Fan , Yuanjie Chen , Dong Pan , Jianhua Zhao , H. Q. Xu

Magnetoresistance oscillations were observed on networks of superconducting ultrathin Nb nanowires presenting evidences of either thermal or quantum activated phase slips. The magnetic transport data, discussed in the framework of different…

Superconductivity · Physics 2014-10-08 C. Cirillo , S. L. Prischepa , M. Trezza , V. P. Bondarenko , C. Attanasio

A range of high quality Ga1-xMnxN layers have been grown by molecular beam epitaxy with manganese concentration 0.2 < x < 10%, having the x value tuned by changing the growth temperature (Tg) between 700 and 590 {\deg}C, respectively. We…

We present a complete numerical calculation and an experimental data analysis of the universal conductance fluctuations in quasi-one-dimension nanowires. The conductance peak density model, introduced in nanodevice research on [Phys. Rev.…

Mesoscale and Nanoscale Physics · Physics 2018-10-11 T. Verçosa , Yong-Joo Doh , J. G. G. S. Ramos , A. L. R. Barbosa

The magnetotransport in phase-separated (Ga,Fe)N containing $\gamma$'-Ga$_y$Fe$_{4-y}$N (0\,$<$\,y\,$<$1) nanocrystals (NCs) is studied in the temperature range between 2\,K and 300\,K. The evolution of the resistivity and of the…

Materials Science · Physics 2020-01-08 A. Navarro-Quezada , M. Aiglinger , B. Faina , K. Gas , M. Matzer , Tian Li , R. Adhikari , M. Sawicki , A. Bonanni

The effects of finite temperature in transport through nanoscopic systems exhibiting uniaxial magnetic anisotropy D, such as molecular magnets, adatoms, or quantum dots side-coupled to a large spin are analyzed in the Kondo regime. The…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Maciej Misiorny , Ireneusz Weymann , Józef Barnaś

We studied structural, optical and magnetic properties of high-quality 5 and 15% Co-doped ZnO films grown by plasma-assisted molecular beam epitaxy (MBE) on (0001)-sapphire substrates. Magnetic force microscopy (MFM) and magnetic…

GaN nanowire ensembles with axial InGaN multi-quantum wells (MQWs) were grown by molecular beam epitaxy. In a series of samples, we varied the In content in the MQWs from almost zero to about 20%. Within the nanowire ensemble, the MQWs…

To understand quantum mechanical transport in ferromagnetic semiconductor the knowledge of basic material properties like phase coherence length and corresponding dephasing mechanism are indispensable ingredients. The lack of observable…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 K. Wagner , D. Neumaier , M. Reinwald , W. Wegscheider , D. Weiss

We report on electrical resistance measurements of an individual carbon nanotube down to a temperature T=20 mK. The conductance exhibits a ln T dependence and saturates at low temperature. A magnetic field applied perpendicular to the tube…

Implementing topological insulators as elementary units in quantum technologies requires a comprehensive understanding of the dephasing mechanisms governing the surface carriers in these materials, which impose a practical limit to the…

We have characterized the conductivity of carbon nanotubes (CNT) fibers enriched in semiconducting species as a function of temperature and pulsed laser irradiation of 266 nm wavelength. While at high temperatures the response approaches an…

We analyze the heat transfer between two nanoparticles separated by a distance lying in the near-field domain in which energy interchange is due to Coulomb interactions. The thermal conductance is computed by assuming that the particles…

Materials Science · Physics 2008-04-18 Agustin Pérez-Madrid , José M. Rubí , Luciano C. Lapas

Raman spectroscopy is utilized to study the magnetic characteristics of heteroepitaxial NiO thin films grown by plasma-assisted molecular beam epitaxy on MgO(100) substrates. For the determination of the N\'eel temperature, we demonstrate a…

Materials Science · Physics 2020-07-24 J. Feldl , M. Budde , C. Tschammer , O. Bierwagen , M. Ramsteiner

Superconducting properties of metallic nano-wires may strongly depend on specific experimental conditions. Here we consider a setup where superconducting phase fluctuations are restricted at one point inside the wire and equilibrium…

Superconductivity · Physics 2020-09-03 Alexey Radkevich , Andrew G. Semenov , Andrei D. Zaikin

A superconductor is influenced by an applied magnetic field. Close to the transition temperature $T_{c}$ fluctuations dominate and the correlation length $\xi $ increases strongly when $T_{c}$ is approached. However, for nonzero magnetic…

Superconductivity · Physics 2007-05-23 T. Schneider

Thermal properties have an outsized impact on efficiency and sensitivity of devices with nanoscale structures, such as in integrated electronic circuits. A number of thermal conductivity measurements for semiconductor nanostructures exist,…