Skyrmions in a density wave state: a mechanism for chiral superconductivity

Abstract

Broken symmetry states characterizing density waves of higher angular momentum in correlated electronic systems are intriguing objects. In the scheme of characterization by angular momentum, conventional charge and spin density waves correspond to zero angular momentum. Here we explore a class of exotic density wave states that have topological properties observed in recently discovered topological insulators. These rich topological density wave states deserve closer attention in not only high temperature superconductors but in other correlated electron states, as in heavy fermions, of which an explicit example will be discussed.The state discussed has non-trivial charge $2e$ skyrmionic spin texture. These skyrmions can condense into a charged superfluid. Alternately, they can fractionalize into merons and anti-merons. The fractionalized particles that are confined in skyrmions in the insulating phase, can emerge at a deconfined quantum critical point, which separates the insulating and the superconducting phases. These fractional particles form a two-component spin-singlet chiral $(d_{x^2-y^2}\pm i{d}_{xy})$ wave superconducting state that breaks time reversal symmetry. Possible connections of this exotic order to the superconducting state in the heavy-fermion material URu${}_2$Si${}_2$ are suggested. The direct evidence of such a chiral superconducting state is polar Kerr effect that was observed recently.

27 pages, 9 figures; In a special issue on skyrmions of IJMPB, ed. M. Rho and I. Zahed

References in corpus (15)

• "Deconfined" quantum critical points
• Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm
• Topological Mott Insulators
• Rotational Symmetry Breaking in the Hidden-Order Phase of URu2Si2
• Exotic Superconducting Properties in the Electron-Hole Compensated Heavy Fermion `Semimetal' URu2Si2
• Evidence for broken time-reversal symmetry in the superconducting phase of URu${}_2$Si${}_2$
• Deconfined criticality, runaway flow in the two-component scalar electrodynamics and weak first-order superfluid-solid transitions
• Hartree-Fock Computation of the High-Tc Cuprate Phase Diagram
• Time-reversal symmetry breaking by a $(d+id)$ density-wave state in underdoped cuprate superconductors
• Berry phase mediated topological thermoelectric transport in gapped single and bilayer graphene
• Bulk evidence for a time reversal symmetry broken superconducting state in URu2Si2
• Discovery of an Excited Pair State in Superfluid 3He
• Meissner effect without superconductivity from a chiral d-density wave
• Charge-$2e$ Skyrmion condensate in a hidden order state
• Superconducting phase within the hidden-order state of the heavy-fermion material $\mathrm{UR}{\mathrm{u}}_2\mathrm{S}{\mathrm{i}}_2$

Cited by in corpus (3)

• Chiral Superconductors
• Skyrmion Superconductivity: DMRG evidence for a topological route to superconductivity
• Time Reversal Symmetry Breaking in the B Phase of the Heavy Fermion Superconductor PrOs${}_4$Sb${}_{12}$