相关论文: Resonating valence bonds and mean-field d-wave sup…
While not widely recognized, electronic correlations might play an important role in graphene. Indeed, Pauling's resonance valence bond (RVB) theory for the pp-bonded planar organic molecules, of which graphene is the infinite extension,…
The superconducting proximity effect induces pairing correlations in metallic systems via Andreev scattering. This effect is particularly intriguing in graphene, as it enables two-dimensional superconductivity that is tunable through…
A highly unconventional superconducting state with a spin-singlet $d_{x^2-y^2}\pm id_{xy}$-wave, or chiral d-wave, symmetry has recently been proposed to emerge from electron-electron interactions in doped graphene. Especially graphene…
Unconventional superconductors have been long sought for their potential applications in quantum technologies and devices. A key challenge impeding this effort is the difficulty associated with probing and characterizing candidate materials…
Superconducting proximity effects in graphene have received a great deal of attention for over a decade now. This has unveiled a plethora of exotic effects linked to the specificities of graphene's electronic properties. The vast majority…
The two-dimensional (2D) Hubbard model is widely believed to contain the key ingredients of high-temperature superconductivity in cuprate materials. Here, we report a constrained path quantum Monte Carlo (CPQMC) study of the square-lattice…
It has been argued that inhomogeneity generally can enhance superconductivity in the cuprate high-Tc materials. To check the validity of this claim, we study d-wave superconductivity on the checkerboard Hubbard model on a square lattice…
Within the $t$--$J$ model Hamiltonian we present a RVB mean field theory directly in terms of dopant particles. We apply this theory to $\mathrm{Na}_{x}\mathrm{CoO_{2}}\cdot y% \mathrm{H_{2}0}$ and show that the resulting phase diagram…
Graphene is at the forefront of condensed matter sciences, because of a variety of interesting phenomena it supports. If graphene could support high Tc superconductivity, after doping for example, it will make it even more valuable. Some…
Superconductivity in strongly correlated systems is a remarkable phenomenon that attracts a huge interest. The study of this problem is relevant for materials as the high Tc oxides, pnictides and heavy fermions. In this work we study a…
Although mean field theories have been very successful to predict a wide range of properties for solids, the discovery of high temperature superconductivity in cuprates supported the idea that strongly correlated materials cannot be…
Understanding the origin of superconductivity in correlated two-dimensional materials is a key step in leveraging material engineering techniques for next-generation nanoscale devices. The recent demonstration of superconductivity in Bernal…
We view $MgB_2$ as electronically equivalent to (non-staggered) graphite ($B^-$ layer) that has undergone a zero gap semiconductor to a superconductor phase transition by a large c-axis (chemical) pressure due to $Mg^{++}$ layers. Further,…
We reexamine the possibility of d-wave superconductivity in the hole-doped two-dimensional Hubbard model. In terms of the gauge field description of the spin fluctuations, we show that d-wave superconductivity is unstable in the…
Graphene is known to be non-superconducting. However, surprising superconductivity is recently discovered in a flat-band in a twisted bi-layer graphene. Here we show that superconductivity can be more easily realized in topological…
Recent experiments show how a bilayer graphene twisted around a certain magic angle becomes superconducting as it is doped into a region with approximate flat bands. We investigate the mean-field $s$-wave superconducting state in such a…
The interplay between antiferromagnetism and d-wave superconductivity is studied in a mean-field approximation for a generic microscopic Hamiltonian with short-range repulsion and near-neighbor attraction. In the presence of competing…
Many theoretical approaches find d-wave superconductivity in the prototypical one-band Hubbard model for high-temperature superconductors. At strong-coupling (U > W, where U is the on-site repulsion and W=8t the bandwidth) pairing is…
Disorder and doping have profound effects on the intrinsic physical mechanisms of superconductivity. In this paper, we employed the determinant quantum Monte Carlo method to investigate the symmetry-allowed superconducting orders on the…
Combining mean-field and renormalization group analyses, here we unveil the nature of recently observed superconductivity and parent metallic states in chemically doped rhombohedral trilayer graphene, subject to external electric…