Gapless fermions and gauge fields in dielectrics

Topological order and the deconfinement transition in the(2+1)-dimensional compact Abelian Higgs model

“…This corresponds to allowing twists in the boundary conditions for A in Eq. (1) or (2). 29 Let the winding number M ν be the number of such flux line crossings (counted with signs) for a cross-section perpendicular to the ν-direction, i.e.,…”

“…1,2,3,4,5,6,7,8,9,10 The splintering of the electron into a neutral spinon and a charged spinless holon, and the resulting spin-charge separation, was proposed early after the discovery of the superconducting high-T c cuprates as a route to explain the nonFermi liquid behavior observed in these systems. The fractionally charged Laughlin quasi-particles in the fractional quantum hall effect is another famous example.…”

“…Usually, the fractionalization in dimensions larger than one, is imagined to occur via a confinement-deconfinement transition of an effective low energy gauge theory description of the system. 11,12 A number of such gauge theories have been proposed for the underdoped cuprates, including U (1), 1,2,3,4,5,6,7,8,13,14 SU (2), 9 and Z 2 10 -gauge theories. In addition, the possibility of fractionalized phases in models containing only bosons has been proposed.…”

Mutual Chern-Simons effective theory of doped antiferromagnets

“…To characterize such a Hilbert space restriction, a spin-charge separation description, namely, by introducing 2,3,4 spinless "holon" of charge +e and neutral spin-1/2 "spinon" as the essential building blocks of the restricted Hilbert space, has become an effective and useful way. Here "holons" and "spinons" do not necessarily turn out to be true low-lying elementary excitations in the end, because generally local gauge field(s) will emerge 5,6 to mediate interactions between these "holons" and "spinons", and may even lead to the confinement of them if either a true spin-charge separation does not exist or the decomposition is not done in a correct way. In general, one always ends up with a gauge theory description for doped Mott insulators where the gauge interaction can greatly influence the low-energy dynamics of the charge and spin degrees of freedom.…”

Spin–charge gauge compositeness of electron in HTS: Hints from metal–insulator crossover and entropy behavior

“…The coexistence of FS and insulating behavior of ρ is instead easily accommodated in a slave-particle gauge theory which implies a "gauge compositeness" of the electron. In these approaches, due to the gauge string binding together fermionic and bosonic constituents of the "electron", the velocity of the electron resonance determining the conductivity is dominated by the slowest constituent (Ioffe-Larkin rule [9]). Since the fermionic constituent shows a metallic behavior, exhibiting a FS, the electron resonance has a metallic/insulating behavior if the bosonic constituent does.…”