Related papers: Competing order, Fermi surface reconstruction, and…
We propose a simple effective model to describe FeAs superconductors. This model is based on the assumption of a local spin-density-wave (SDW) order, with its magnetization direction allowed to fluctuate. It is shown that the long-range…
We consider states with a charge- or spin-density wave order parameter which is odd in frequency, so that the order parameter vanishes at zero frequency and there is a conventional Fermi surface. Such states break translational symmetry…
High-temperature superconductivity occurs as copper oxides are chemically tuned to have a carrier concentration intermediate between their metallic state at high doping and their insulating state at zero doping. The underlying evolution of…
Incommensurate (IC) charge-order (CO) and spin density wave (SDW) order in electron doped SrMn1-xWxO3-{\delta} (x= 0.08 to 0.1875) have been studied using neutron diffraction.The study highlights the drastic effect of electron doping on the…
In $\rm Sr_2RuO_4$ the spin excitation spectrum is dominated by incommensurate fluctuations at q=(0.3 0.3 q$_z$), which arise from Fermi-surface nesting. We show that upon Ti substitution, known to suppress superconductivity, a short range…
The Fourier transform of the observed magnetic quantum oscillations (MQO) in YBa$_{2}$Cu$_{3}$O$_{6+\delta }$ high-temperature superconductors has a prominent low-frequency peak with two smaller neighbouring peaks. The separation and…
Hidden spin-density waves (hSDW) with Neel ordering vector (pi,pi) have been proposed recently as parent groundstates to electron-doped iron-selenide superconductors. Doping such groundstates can result in visible electron-type Fermi…
Understanding the pseudogap phase in hole-doped high temperature cuprate superconductors remains a central challenge in condensed matter physics. From a host of recent experiments there is now compelling evidence of translational symmetry…
Unconventional magnetism represents a class of metallic states whose Fermi surfaces exhibit spin-dependent splittings under the non-trivial representations of the rotation group. The $d$-wave $\alpha$-phase unconventional magnetic state,…
Superconductivity in alkali-intercalated iron selenide, with T_c's of 30K and above, may have a different origin than that of the other Fe-based superconductors, since it appears that the Fermi surface does not have any holelike sheets…
Novel imaging methods show that the mobile dopants in optimum doped La$_2$CuO$_{4+y}$ (LCO) get self-organized, instead of randomly distributed. Rigid-band models fail because of ordering of dopants and supercell calculations are required…
We analyze a model of itinerant electrons interacting through a quadrupole density-density repulsion in three dimensions. At the mean field level, the interaction drives a continuous Pomeranchuk instability towards $d$-wave, spin-triplet…
We show that the d-wave ordering in particle-hole channels, dubbed d-wave checkerboard order, possesses important physics that can sufficiently explain the scanning tunneling microscopy (STM) results in cuprates. A weak d-wave checkerboard…
Charge modulations are considered as a leading competitor of high-temperature superconductivity in the underdoped cuprates, and their relationship to Fermi surface reconstructions and to the pseudogap state is an important subject of…
Experiments carried over the last years on the underdoped cuprates have revealed a variety of symmetry-breaking phenomena in the pseudogap state. Charge-density waves, breaking of $C_{4}$ rotational symmetry as well as time-reversal…
Recent experiments in the underdoped regime of the hole-doped cuprates have found evidence for an incommensurate charge density wave state. We present an analysis of the charge ordering instabilities in a metal with antiferromagnetic…
It has long been known that two-dimensional metals with antiferromagnetic exchange interactions have a weak-coupling instability to the superconductivity of spin-singlet, d-wave electron pairs. We examine additional possible instabilities…
We discuss the low energy theory of two-dimensional metals near the onset of spin density wave order. It is well known that such a metal has a superconducting instability induced by the formation of spin-singlet pairs of electrons, with the…
We studied the quantum oscillations in superconducting vortex mixed states with d-wave pairing. We showed that the Onsager relation does not always apply. Furthermore, at mean field level the quantum oscillations from electron pockets are…
Charge order--ubiquitous among correlated materials--is customarily described purely as an instability of the electronic structure. However, the resulting theoretical predictions often do not match high-resolution experimental data. A…