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Related papers: Intrinsic Superconductivity at 25 K in Highly Orie…

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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

The carrier density in tens of nanometers thick graphite samples (multi-layer-graphene, MLG) has been modified by applying a gate voltage ($V_g$) perpendicular to the graphene planes. Surface potential microscopy shows inhomogeneities in…

Superconductivity · Physics 2014-02-04 A. Ballestar , P. Esquinazi , J. Barzola-Quiquia , S. Dusari , F. Bern , R. R. da Silva , Y. Kopelevich

We report the observation of superconductivity in high-quality Cd$_2$Re$_2$O$_7$ single crystals with room-temperature pyrochlore structure. Resistivity and ac susceptibility measurements establish an onset transition temperature…

Superconductivity · Physics 2009-11-07 R. Jin , J. He , S. McCall , C. S. Alexander , F. Drymiotis , D. Mandrus

A recently reported transition in the electrical resistance of different natural graphite samples suggests the existence of superconductivity at room temperature. To check whether dissipationless electrical currents are responsible for the…

Superconductivity · Physics 2017-05-30 Markus Stiller , Pablo D. Esquinazi , Christian E. Precker , José Barzola-Quiquia

In this work we investigated correlations between the internal microstructure and sample size (lateral as well as thickness) of mesoscopic, tens of nanometer thick graphite (multigraphene) samples and the temperature $(T)$ and field $(B)$…

Materials Science · Physics 2015-05-13 J. Barzola-Quiquia , J. -L. Yao , P. Rödiger , K. Schindler , P. Esquinazi

Surface superconductivity in rhombohedral graphite is a robust phenomenon which can exist even when higher order hoppings between the layers lift the topological protection of the surface flat band and introduce a quadratic dispersion of…

Superconductivity · Physics 2013-05-13 N. B. Kopnin , M. Ijäs , A. Harju , T. T. Heikkilä

We have previously found experimental evidence for several quantum phenomena in oxygen-ion implanted of hydrogenated graphite: ferromagnetism, antiferromagnetism, paramagentism, triplet superconductivity, Andreev states, Little-Parks…

Superconductivity · Physics 2023-11-23 Nadina Gheorghiu , Charles R. Ebbing , Timothy J. Haugan

Recently, Ksenofontov et al (arXiv:2510.03256) observed ambient pressure room-temperature superconductivity in graphite intercalated with lithium-based alloys with transition temperature (according to magnetization measurements) $T_c=330$…

General Physics · Physics 2026-01-01 E. F. Talantsev

Search for new high-temperature superconductors and insight into their superconducting mechanism are of fundamental importance in condensed matter physics. The discovery of near-room temperature superconductivity at more than a million…

We consider superconducting properties of a two-dimensional Dirac material such as graphene under strain that produces a flat band spectrum in the normal state. We show that in the superconducting state, such a model results in a highly…

Superconductivity · Physics 2016-06-22 V. J. Kauppila , F. Aikebaier , T. T. Heikkilä

The satisfactory explanation of abnormal electromagnetics in thin graphite-like carbon films till now is absent. The most comprehensible explanation may be the high-temperature superconductivity (HTSC). Times of spasmodic switching of…

Superconductivity · Physics 2007-05-23 S. G. Lebedev , V. E. Yants , A. S. Lebedev

We propose an explanation for the apparent semimetal-insulator transition observed in highly oriented pyrolitic graphite in the presence of magnetic field perpendicular to the layers. We show that the magnetic field opens an excitonic gap…

Condensed Matter · Physics 2009-11-07 D. V. Khveshchenko

The discovery of superconductivity with a critical temperature exceeding 55 K in the iron-oxypnictides and related compounds has quite suddenly given the community a new set of materials - breaking the tyranny of copper. This new class of…

Magic-angle twisted multilayer graphene stands out as a highly tunable class of moir\'e materials that exhibit strong electronic correlations and robust superconductivity. However, understanding the relations between the low-temperature…

We present measurements of the electric potential fluctuations on the surface of highly oriented pyrolytic graphite using electrostatic force and atomic force microscopy. Micrometric domain-like potential distributions are observed even…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Yonghua Lu , M. Munoz , C. S. Steplecaru , Cheng. Hao , Ming Bai , N. Garcia , K. Schindler , P. Esquinazi

We have discovered that samples of a new material produced by special processing of crystals of Sr2RuO4 (which is known to be a triplet superconductor with Tc values ~1.0-1.5K) exhibit signatures of superconductivity (zero DC resistance and…

Epitaxial graphene films have been formed on the C-face of semi-insulating 4H-SiC substrates by a high temperature sublimation process. Nano-scale square antidot arrays have been fabricated on these graphene films. At low temperatures,…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 T. Shen , Y. Q. Wu , M. A. Capano , L. R. Rokhinson , L. W. Engel , P. D. Ye

The electrical conductivity of suspended graphene has recently been measured for the first time, and found to behave as \sigma ~ \sqrt{|n|} as expected for Dirac quasiparticles at large carrier density. The charge inhomogeneity is strongly…

Strongly Correlated Electrons · Physics 2016-08-14 Joaquín E. Drut , Timo A. Lähde , Eero Tölö

Trying to dope graphite flakes we found that the magnetization of pure, several tens of micrometers grain size graphite powder and after a simple treatment with pure water shows clear and reproducible granular superconducting behavior with…

Superconductivity · Physics 2013-07-09 T. Scheike , W. Böhlmann , P. Esquinazi , J. Barzola-Quiquia , A. Ballestar , A. Setzer