English
Related papers

Related papers: Landau Level Quantization and Possible Superconduc…

200 papers

The interlayer magnetoresistance $\rho_{zz}$ of the organic metal \cuscn is studied in fields of up to 45 T and at temperatures $T$ from 0.5 K to 30 K. The peak in $\rho_{zz}$ seen in in-plane fields, a definitive signature of interlayer…

Superconductivity · Physics 2009-11-11 John Singleton , PA Goddard , A Ardavan , AI Coldea , SJ Blundell , RD McDonald , S Tozer , JA Schlueter

We review experimental results, from transport to magnetization measurements, on different graphite samples, from bulk oriented graphite, thin graphite films to transmission electron microscope lamellae, that indicate the existence of…

Superconductivity · Physics 2013-12-17 Pablo Esquinazi

The in-plane resistivity, Hall resistivity and magnetization of graphite were investigated in pulsed magnetic fields applied along the \textit{c}-axis. The Hall resistivity approaches zero at around 53 T where the in-plane and out-of-plane…

Strongly Correlated Electrons · Physics 2015-05-07 Kazuto Akiba , Atsushi Miyake , Hiroshi Yaguchi , Akira Matsuo , Koichi Kindo , Masashi Tokunaga

We present magnetization measurements for the upper critical field $H_{c2}$ on aligned Na$_{x}$(H$_{3}$O)$_{z}$CoO$_{2}\cdot y$H$_{2}$O superconductors with magnetic field parallel to CoO$_2$ layers. The temperature-dependent part of the…

Superconductivity · Physics 2007-10-04 Zhi Ren , Chunmu Feng , Zhu'an Xu , Minghu Fang , Guanghan Cao

We have studied the magnetization of various, well characterized samples of highly oriented pyrolitic graphite (HOPG), Kish graphite and natural graphite to investigate the recently reported ferromagnetic-like signal and its possible…

Strongly Correlated Electrons · Physics 2009-11-07 P. Esquinazi , A. Setzer , R. Hoehne , C. Semmelhack , Y. Kopelevich , D. Spemann , T. Butz , B. Kohlstrunk , M. Loesche

We report conduction electron spin resonance measurements performed on highly oriented pyrolitic graphite samples between 10 K and 300 K using S (f = 4 GHz), X (f = 9.4 GHz), and Q (f = 34.4 GHz) microwave bands for the external dc-magnetic…

Condensed Matter · Physics 2009-11-07 M. S. Sercheli , Y. Kopelevich , R. Ricardo da Silva , J. H. S. Torres , C. Rettori

In-plane resistivity measurements as a function of temperature, magnetic field and its orientation with respect to the crystallographic $ab-$plane were used to study the upper critical field, $H_{c2}$, of two overdoped compositions of the…

Superconductivity · Physics 2013-08-22 J. Murphy , M. A. Tanatar , D. Graf , J. S. Brooks , S. L. Bud'ko , P. C. Canfield , V. G. Kogan , R. Prozorov

In the last 43 years several hints were reported suggesting the existence of granular superconductivity above room temperature in different graphite-based systems. In this paper some of the results are reviewed, giving special attention to…

In this work we show that for a quasi-2D system of size $\Omega$ and thickness $t$ the resistance goes as $(2\rho/\pi t)\ln(\Omega/W)$, diverging logarithmically with the size. Measurements in highly oriented pyrolytic graphite (HOPG) as…

Strongly Correlated Electrons · Physics 2008-05-28 N. García , P. Esquinazi , J. Barzola-Quiquia , B. Ming , D. Spoddig

We have measured the temperature and magnetic field dependence of the Hall coefficient ($R_{\rm H}$) in three, several micrometer long multigraphene samples of thickness between $\sim 9~$to $\sim 30$~nm in the temperature range 0.1 to 200~K…

Superconductivity · Physics 2014-11-07 P. Esquinazi , J. Krüger , J. Barzola-Quiquia , R. Schönemann , T. Herrmannsdörfer , N. García

We study here the onset of charge density wave instabilities in quantum Hall systems at finite temperature for Landau level filling $\nu>4$. Specific emphasis is placed on the role of disorder as well as an in-plane magnetic field. Beyond…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Tudor Stanescu , Ivar Martin , Philip Phillips

Graphite exhibits multi-stage phase transitions in the quantum-limit states realized by magnetic fields applied along the c-axis. Despite extensive studies on this phenomenon, the origin remains a matter of debate to this day. We performed…

Strongly Correlated Electrons · Physics 2025-12-16 Masashi Tokunaga , Kazuto Akiba , Hiroshi Yaguchi , Akira Matsuo , Koichi Kindo

Exposure of highly oriented pyrolytic graphite to bromine vapor gives rise to in-plane charge conductivities which increase monotonically with intercalation time toward values (for ~6 at% Br) that are significantly higher than Cu at…

Materials Science · Physics 2013-05-29 S. Tongay , J. Hwang , D. B. Tanner , H. K. Pal , D. Maslov , A. F. Hebard

frared reflectance spectroscopy at 4K in fields up to 31T. Both Schr\"odinger-like (K-point) and Dirac-like (H-point) Landau level transitions have been observed, and their magnetic field dispersion are analyzed by a newly-derived limiting…

Materials Science · Physics 2015-05-28 L. -C. Tung , P. Cadden-Zimansky , J. Qi , 1 Z. Jiang , D. Smirnov

Basal plane resistivity of expanded graphite was studied under simultaneous influence of hydrostatic pressure up to 1.8 GPa and magnetic field 0.8 T in the 77-300 K temperature region. Magnetic field induces negative magnetoresistance in…

Materials Science · Physics 2014-06-17 V. V. Slyusarev , P. I. Polyakov

In this work, we have studied the effects from increasing the strength of the applied electric field on the charge transport of hydrogenated graphitic fibers. Resistivity measurements were carried out for direct currents in the nA - mA…

Materials Science · Physics 2020-05-19 Nadina Gheorghiu , Charles R. Ebbing , Timothy J. Haugan

It has been reported that graphite hosts room temperature superconductivity. Here we provide new results that confirm these claims on different samples of highly oriented pyrolytic graphite (HOPG) and commercial flexible graphite gaskets…

We demonstrate direct evidence of possible surface superconductivity on small, well-shaped MgB2 single crystals. Transport measurements in the range H < 1.6 Hc2^c, where Hc2^c is the bulk upper critical field for the c axis, show non-Ohmic…

In spite of 40 years of experimental studies and several theoretical proposals, an overall interpretation of the complex behavior of the magnetoresistance (MR) of multilayer graphene, i.e. graphite, at high fields ($B \lesssim 70~$T) and in…

We show that rhombohedral graphite may support surface superconductivity with an unusual relation between the BCS coupling constant and the order parameter. This feature results from the properties of the states localized on the graphite…

Superconductivity · Physics 2019-08-15 N. B. Kopnin , T. T. Heikkila