相关论文: Nodeless $s$-Wave Superconducting Phases in Cuprat…
High-temperature superconductivity is reported in a series of compositionally-complex cuprates with varying degrees of size and spin disorder. Three compositions of Y-site alloyed YBa$_2$Cu$_3$O$_{7-x}$, i.e., (5Y)BCO, were prepared using…
The minimal theory of spin of gapless quasiparticles coupled to fluctuating vortex defects in the phase of the d-wave superconducting order parameter at T=0 is studied. With the proliferation of the vortex loops the theory reduces to the…
We report the phase diagram of Nd$_{1-x}$Sr$_x$NiO$_2$ infinite layer thin films grown on SrTiO$_3$. A superconducting dome spanning $0.125 < x < 0.25$ is found, remarkably similar to cuprates, albeit over a narrower doping window. However,…
Pairing in the cuprate high-temperature superconductors and its origin remain among the most enduring mysteries in condensed matter physics. With cross-sectional scanning tunneling microscopy/ spectroscopy, we clearly reveal the…
Although there is no complete theory of high temperature superconductivity, the importance of CuO$_2$ planes in cuprate superconductors is confirmed from both theory and experiments. Strong Coulomb repulsion between electrons on the CuO$_2$…
The $d$-wave pairing symmetry has long been considered a defining feature of high-temperature superconductivity in cuprates. In this work, we reveal that $s$-wave pairing states exhibit variational energies comparable to the $d$-wave state…
We develop a minimal non-BCS model for the CuO$_2$ planes with the on-site Hilbert space reduced to only three effective valence centers CuO$_4$ with different charge, conventional spin, and orbital symmetry, combined in a charge triplet.…
In underdoped cuprates fluctuations of the phase of the superconducting order parameter play a role due to the small superfluid density. We consider the effects of phase fluctuations assuming the exchange of spin fluctuations to be the…
The interplay between different quantum phases plays an important role in strongly correlated systems, such as high-$T_c$ cuprates, quantum spin systems, and ultracold atoms. In particular, the application of effective field theory model…
For the recently discovered cuprate superconductor $\mathrm{Ba_{2}CuO_{3+\delta}}$, we propose a lattice structure which resembles the model considered by Lieb to represent the vastly oxygen-deficient material. We first investigate the…
We formulate a model describing the doping ($x$) and temperature ($T$) dependence of the $ab$-plane and c-axis penetration depth of a cuprate superconductor. The model incorporates the suppression of the superfluid density with underdoping…
We present a theoretical model to show that the transition from an antiferromagnetic (AFM) phase to the $d_{x^2-y^2}$-wave superconductivity occurs through a robust companion of a finite momentum pairing between $({\bf k},\uparrow)$ and…
We determine the phase diagram of the half-filled two-leg ladder both at weak and strong coupling, taking into account the Cu d_{x^2-y^2} and the O p_x and p_y orbitals. At weak coupling, renormalization group flows are interpreted with the…
We compute the topological phase diagram of 2D tetragonal superconductors for the only possible nodeless pairing channels compatible with that crystal symmetry. Subject to a Zeeman field and spin-orbit coupling, we demonstrate that these…
In order to explain the emergence of the anomalous pseudogap state and high-temperature superconductivity in the cuprates, intense research activity over three decades has focused on unravelling the connection between the various…
We study the spin dynamics in underdoped cuprates at low temperatures by considering them as quasi two dimensional d-wave superconductors (dSC) with strong phase fluctuations. An effective theory of spin degrees of freedom of nodal…
The phase diagrams of cuprate superconductors and of QCD at non-zero baryon chemical potential are qualitatively similar. The Neel phase of the cuprates corresponds to the chirally broken phase of QCD, and the high-temperature…
Although charge density wave (CDW) correlations appear to be a ubiquitous feature of the superconducting cuprates, their disparate properties suggest a crucial role for coupling or pinning of the CDW to lattice deformations and disorder.…
We performed scanning tunneling spectroscopic experiments on hole-doped NdBa$_2$Cu$_3$O$_{7-\delta}$. The d$I$/d$V$ curves obtained at 4.2 K are asymmetric with clear peak-dip and hump structures. Energy derivatives of these curves show…
The electron-doped cuprates Pr_{2-x}Ce_xCuO_4 and Nd_{2-x}Ce_xCuO_4 have been studied by electronic Raman spectroscopy across the entire region of the superconducting (SC) phase diagram. The SC pairing strength is found to be consistent…