Related papers: High $T_c$ Superconductivity, Skyrmions and the Be…
We propose a mechanism of high temperature superconductivity from the viewpoint of chirality and Berry phase. It is observed that spin pairing and charge pairing is caused by a gauge force generated by magnetic flux quanta attached to them.…
We suggest that a spin-charge separating ansatz, leading to non-Abelian $SU(2) \otimes U_S(1)$ gauge symmetries in doped antiferromagnets, proposed earlier as a way of describing Kosterlitz-Thouless superconducting gaps at the nodes of the…
We have analysed here the equivalence of RVB states with $\nu=1/2$ FQH states in terms of the Berry Phase which is associated with the chiral anomaly in 3+1 dimensions. It is observed that the 3-dimensional spinons and holons are…
The Chern-Simons bosonization with U(1)xSU(2) gauge field is applied to 2-D t-J model in the limit t >> J, to study the normal state properties of underdoped cuprate superconductors. We prove the existence of an upper bound on the partition…
Electron motion in crystals is governed by the coupling between crystal momentum and internal degrees of freedom such as spin implicit in the band structure. The description of this coupling in terms of a momentum-dependent effective field…
High-transition-temperature (high-Tc) superconductivity develops near antiferromagnetic phases, and it is possible that magnetic excitations contribute to the superconducting pairing mechanism. To assess the role of antiferromagnetism, it…
We present the exact solution of a one-dimensional model of a spin-gapped correlated electron system with hybridization impurities exhibiting both magnetic and mixed-valence properties. The host supports superconducting fluctuations, with a…
From topological viewpoint we have analysed the role of Berry phase in spin pairing mechanism of high $T_c$ superconducting state.
Phase structure of the (2+1)-dimensional model with four-fermion interaction of spin-1/2 quasiparticles (electrons) both in the fermion-antifermion (or chiral) and fermion-fermion (or superconducting) channels is considered at nonzero…
We present a lattice field theory of spins coupled to Dirac fermions, as a model for the doped copper oxide compounds. Both the fermionic and spin degrees of freedom are treated dynamically. The influence of the charge carriers on the…
When superconductivity is suppressed by high magnetic fields in La2-xSrxCuO4, striped antiferromagnetic (AFM) order becomes the magnetic ground state of the entire pseudogap regime, up to its end at the doping p* [M. Frachet, I. Vinograd et…
We show that a Chern-Simons term for a gauge field describing a fluctuation of spins is induced by integrating out hole fields in the presence of spin-orbit coupling which originates from a buckling of the CuO$_2$ plane. Through the…
A review is given of a relativistic non-Abelian gauge theory approach to the physics of spin-charge separation in doped quantum antiferromagnetic planar systems, proposed recently by the authors. Emphasis is put on the effects of constant…
Based on an improved SU(2) slave-boson approach showing coupling between the cha rge and spin degrees of freedom, we derive a phase diagram of high $T_c$ cuprate s which displays both the superconducting and pseudogap phases in the plane of…
I generalize the concept of Berry's geometrical phase for quasicyclic Hamiltonians to the case in which the ground state evolves adiabatically to an excited state after one cycle, but returns to the ground state after an integer number of…
Using the U(1) holon pair slave boson theory [Phys. Rev. B 64, 052501 2001)], we derive a low energy field theory of dealing with both d-wave superconductivity and antiferromagnetism for underdoped cuprates by constructing both the Cooper…
In magnetic systems, electronic bands often acquire nontrivial topological structure characterized by gauge flux distribution in momentum (k)-space. It sometimes follows that the phase of the wavefunctions cannot be defined uniquely over…
Spin-fluctuation-mediated superconductivity is conventionally associated with d_{x^2-y^2} pairing. We show that a generalized model of antiferromagnetic spin fluctuations in three dimensions may also yield a state with formal ``s-wave''…
We consider the SU(2) gauge theory for spin fluctuations in the two-dimensional Hubbard model, where the electron field is fractionalized in terms of spinons and chargons. In this theory, spinons are described by a non-linear sigma model,…
The change-over from phase- to amplitude-fluctuation driven superconductivity is examined for a composite system of free electrons (Fermions with concentration n_F) and localized electron-pairs (hard-core Bosons with concentration n_B) as a…