Ginzburg-Landau theory of a resonating-valence-bond superconductor

Abstract

We present a Ginzburg-Landau formulation of the bosonic resonating-valence-bond ͑RVB͒ theory of superconductivity. The superconducting order parameter is characterized by phase vortices that describe spinon excitations and the transition to the superconducting state occurs when such phase vortices ͑un͒bind. We show that the boson RVB theory always leads to hc/2e flux quanta and that the presence of a trapped spin-1/2 moment inside a vortex core gives rise to observable consequences for the low-temperature field-dependent specific heat. We also show that the cores of magnetic fluxoids exhibit enhanced antiferromagnetic correlations with a midgap energy scale and discuss some experimental implications.

Mutual Chern-Simons effective theory of doped antiferromagnets

“…They are: (i) the restricted Hilbert space of doped Mott insulators, which is characterized by the spin-charge separation formalism with holons and spinons as basic building blocks; (ii) strong short-range AF correlations as provided by the bosonic RVB description in (5), which can naturally grow into an AFLRO state as the doping concentration is reduced to zero; (iii) the mutual singular influence between the charge and spin degrees of freedom as represented by two topological gauge fields, A h ij and A s ij , which mathematically capture the phase string effect identified 23 in the t − J model. Such a mutual interaction has been shown 21,27,28,29 to be responsible for some nontrivial physical properties of the model in close connection with the high-T c materials.…”

“…Furthermore, the weak (logarithmic) confinement of spinons and holons at low energies and low temperatures has been also found 27,28,29 in the phase string model, as opposed to the strong confinement in usual 2D compact U(1) gauge models in slave-boson or slave-fermion theory 30,31 . In the latter, an effective gauge theory may have a serious infrared divergence 6,7 which makes the gauge theory very difficult to deal with mathematically.…”

Superconductivity from Repulsion: Ginzburg–Landau Phenomenology of Cuprates

“…In the case under consideration, real magnetic field due to orbital currents in (24) can be associated with a gauge field which links the charge and orbital current degrees of freedom (ψ and α, respectively). This field is similar to the gauge fields introduced into Ginzburg-Landau functional in boson version of spin-charge separation scheme [23].…”

Bosonic resonating valence bond wave function for doped Mott insulators

“…Thus, each spin automatically carries a phase or supercurrent vortex, called a spinon-vortex, in the state described by |Ψ G . This was first identified in previous work based on the effective theory 21,22 .…”

“…Nevertheless, ∆ 0 ij = 0 in (59) is a meaningful definition and description of a low temperature pseudogap ground state, called the spontaneous vortex phase 21 . In this phase, each unpaired neutral spin (spinon) always carries a ±2π supercurrent vortex, known as a spinon-vortex 22 . We postpone further discussion of the spinon-vortices to Sec.…”