Related papers: Thickness-dependent phase transition in graphite u…
We studied, by scanning tunneling microscopy, the morphology of nanopits of monolayer depth created at graphite surfaces by hydrogen plasma etching under various conditions such as H$_2$ pressure, temperature, etching time, and RF power of…
We study the effects of an in-plane magnetic field on the ground state properties of both gapless and gapped graphene sheets within Random Phase Approximation. The critical magnetic field which leads to a fully spin polarized phase…
We present ab initio many-body calculations of the optical absorption in bulk graphite, graphene and bilayer of graphene. Electron-hole interaction is included solving the Bethe-Salpeter equation on top of a GW quasiparticle electronic…
MBE-grown, 5 nm-thick annealed Ga0.95Mn0.05As films with Tc~90K demonstrate transition from metallic to insulating state below To~10K, where sheet resistances Rsh~h/e2 and both longitudinal Rxx and transverse Rxy components become…
The second layer of $^4$He films adsorbed on a graphite substrate is an excellent experimental platform to study the interplay between superfluid and structural orders. Here, we report a rigid two-frequency torsional oscillator study on the…
Phase fluctuations in finite thickness layered superconducting films are studied theoretically. The model consists of a set of layers, coupled to each other via a gradient-like term in the phase-only action. It is shown that the effective…
Exploring a backgated low density two-dimensional hole sample in the large $r_s$ regime we found a surprisingly rich phase diagram. At the highest densities, beside the $\nu=1/3$, 2/3, and 2/5 fractional quantum Hall states, we observe both…
Strongly correlated quantum matter exhibits a rich variety of remarkable properties, but the organizing principles that underlie the behavior remain to be established. Graphene heterostructures, which can host narrow moire electron bands…
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…
The electric field induced quantum phase transition from topological to conventional insulator has been proposed as the basis of a topological field effect transistor [1-4]. In this scheme an electric field can switch 'on' the ballistic…
It is thought that strong electron correlation in an insulating parent phase would enhance a critical temperature (Tc) of superconductivity in a doped phase via enhancement of the binding energy of a Cooper pair as known in high-Tc…
We use ultrafast electron crystallography to study structural changes induced in graphite by a femtosecond laser pulse. At moderate fluences of ~< 21mJ/cm^2, lattice vibrations are observed to thermalize on a time scale of ~8ps. At higher…
Dynamic control of conductivity and optical properties via atomic structure changes is of tremendous technological importance in information storage. Energy consumption considerations provide a driving force toward employing thin materials…
Transition metal oxides possess complex free energy surfaces with competing degrees of freedom. Photoexcitation allows shaping of such rich energy landscapes. In epitaxially strained $\mathrm{La_{0.67}Ca_{0.33}MnO_3}$, optical excitation…
Recent experimental discoveries of superconductivity and other exotic electronic states in twisted bilayer graphene (TBG) call for a reconsideration of our traditional theories of these states, usually based on the assumption of the…
We realize superconductor-insulator transitions (SIT) in mechanically exfoliated Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (BSCCO) flakes and address simultaneously their transport properties as well as the evolution of density of states.…
Topological insulators with intrinsic magnetic order are emerging as an exciting platform to realize fundamentally new excitations from topological quantum states of matter. To study these systems and their physics, people have proposed a…
We consider the zero-filled quantum-Hall ferromagnetic state of bilayer graphene subject to a kink-like perpendicular electric field, which generates domain walls in the electronic state and low-energy collective modes confined to move…
We study the possibility of excitonic pairing in layered degenerate semimetals such as graphite, where the electron density of states almost vanishes at the Fermi level and, therefore, the Coulomb interactions remain essentially unscreened.…
We suggest that physics underlying the recently observed removal of sublattice and spin degeneracies in graphene in a strong magnetic field describes a phase transition connected with the generation of an excitonic gap. The experimental…