相关论文: Spin-wave condensation and quantum melting of long…

We consider two-dimensional t-J-V model. The wave function of the ground state is constructed. We demonstrate that the doping by holes results in condensation of the spin-waves, destruction of the long-range antiferromagnetic order and…

Long-range $(r \sim p_F^{-1} \gg lattice \ spacing)$ spin-wave exchange produces a very strong pairing of the holes. The different symmetry solutions of BCS-type equation for the superconducting gap $\Delta$ are found. The most strong…

The proximity of antiferromagnetic order in high-temperature superconducting materials is considered a possible clue to the electronic excitations which form superconducting pairs. Here we study the transverse and longitudinal spin…

A many-body wavefuction is postulated, which is sufficiently general to describe superconducting pair-correlations, and/or spin-correlations, which can occur either as long-range order or as finite-range correlations. The proposed…

A microscopic theory of spin excitations in strongly-correlated electronic systems within the t-J model is discussed. An exact representation for the dynamic spin susceptibility is derived. In the normal state, the excitation spectrum…

We study collective spin excitations in two-dimensional diluted magnetic semiconductors, placed into external magnetic field. Two coupled modes of the spin waves (the electron and ion modes) are found to exist in the system along with a…

Results for pseudogaps are obtained from a band model, where the stability of the gap depends on the amplitudes of vibrational displacements, or magnetic moments, and their coupling to electrons. A one-particle gap is favored by normal…

Several series of shallow large-size ($l \gg lattice~ spacing$) two-hole bound states are found in the two-dimensional t-J model. Their binding energies depend exponentially on the inverse value of the hole-spin-wave coupling constant.…

A relaxation-function theory for the dynamic spin susceptibility in the $t$--$J$ model is presented. By a sum-rule-conserving generalized mean-field approximation (GMFA), the two-spin correlation functions of arbitrary range, the staggered…

We discuss the possible existence of a spin-gap phase in the low-doping regime of strongly-correlated two-dimensional electrons within the gauge field description of the t-J model. The spin-gap phase was recently shown by Ubbens and Lee to…

Using computational techniques, it is shown that pairing is a robust property of hole doped antiferromagnetic (AF) insulators. In one dimension (1D) and for two-leg ladder systems, a BCS-like variational wave function with long-bond…

Within the fermion-spin theory, the physical properties of the electron pairing state in the copper oxide materials are discussed. According to the common form of the electron Cooper pair, it is shown that there is a coexistence of the…

We study numerically the hole pairing induced by spin-wave exchange. The contact hole-hole interaction is taken into account as well. It is assumed that antiferromagnetic order is preserved at all scales relevant to pairing. The strongest…

We analyze the real-space paired state with the $\mathbf{k}$-dependent superconducting gap in the presence of Rashba type spin-orbit coupling and external magnetic field. We show that the $extended$ $s$-$wave$ pairing symmetry is the most…

The quantum condensate of Cooper-pairs forming a superconductor was originally conceived to be translationally invariant. In theory, however, pairs can exist with finite momentum $Q$ and thereby generate states with spatially modulating…

The coupling of the spin of electrons to their motional state lies at the heart of recently discovered topological phases of matter. Here we create and detect spin-orbit coupling in an atomic Fermi gas, a highly controllable form of quantum…

A spin-charge recombination route to superconductivity, proposed earlier (1992)], is examined using the Schwinger boson representation of the t-J model. The representation is known to work well at half-filling. It was shown in the earlier…

The spin excitations in the antiferromagnetic phase of half-filled Kondo lattice model are studied by means of the decoupling approximation for spin Green's function. The spin-wave spectrum is calculated as a function of Kondo coupling, and…

We investigate entanglement of two electron spins forming Cooper pairs in an s-wave superconductor. The two-electron space-spin density matrix is obtained from the BCS ground state using a two-particle Green's function. It is demonstrated…

To investigate the non-Fermi liquid behavior we consider the extended two-dimensional t-J model which includes additional hopping t''. In the regime t,J << t'' we were able to solve the model analytically. It has a very rich phase diagram…