Type‐III Superconductivity

Abstract

Superconductivity remains one of most fascinating quantum phenomena existing on a macroscopic scale. Its rich phenomenology is usually described by the Ginzburg–Landau (GL) theory in terms of the order parameter, representing the macroscopic wave function of the superconducting condensate. The GL theory addresses one of the prime superconducting properties, screening of the electromagnetic field because it becomes massive within a superconductor, the famous Anderson–Higgs mechanism. Here the authors describe another widely‐spread type of superconductivity where the Anderson–Higgs mechanism does not work and must be replaced by the Deser–Jackiw–Templeton topological mass generation and, correspondingly, the GL effective field theory must be replaced by an effective topological gauge theory. These superconductors are inherently inhomogeneous granular superconductors, where electronic granularity is either fundamental or emerging. It is shown that the corresponding superconducting transition is a 3D generalization of the 2D Berezinskii–Kosterlitz–Thouless vortex binding–unbinding transition. The binding–unbinding of the line‐like vortices in 3D results in the Vogel‐Fulcher‐Tamman scaling of the resistance near the superconducting transition. The authors report experimental data fully confirming the VFT behavior of the resistance.

Superconductors without Symmetry Breaking

“…This superconductivity mechanism can be generalized to any dimension [10,11]. In (3+1) dimensions, the topological phase transition is the Vogel-Fulcher-Tamman (VFT) transition [18], which has been experimentally confirmed in NbTin sample of 86 nm thickness [12]. BKT scaling in (2+1) dimensions, VFT scaling in (3+1) dimensions, and the vanishing of H c1 are, thus, the hallmarks of type-III superconductivity.…”

“…In type-III superconductors, the superconducting gap is not opened through the Higgs mechanism but through a topological mechanism [19]. As it has been shown in [10][11][12], the infrared-dominant term in the effective action that describes type-II superconductors is the topological Chern-Simons (CS) [19] term in 2D and the BF [20] term in 3D. In the effective action for the electromagnetic field, the presence of these topological terms generates a gauge-invariant mass for the photon, as we will show.…”

“…In type-III superconductors, there is only a gauge scale λ and no Higgs core. At zero temperature, they are characterized by the vanishing of the lower critical field H c1 [12]. This is a crucial difference with respect to type-I superconductors, in which magnetic flux never penetrates the sample, and type-II supeconductors, in which magnetic flux penetrates above H c1 ̸ = 0.…”

“…In [10,11], a new type of superconductivity, later called type-III superconductivity [12], was proposed. In type-III superconductors, there is only a gauge scale λ and no Higgs core.…”

Gauge Theories of Josephson Junction Arrays: Why Disorder Is Irrelevant for the Electric Response of Disordered Superconducting Films

“…This means that Josephson currents of charges percolate through the sample, establishing global superconductivity. This superconductivity, with dissipationless vortices whose confinement/deconfinement drives the thermal phase transition to a resistive state is a type-III superconductivity, not described by the usual Ginzburg-Landau theory [26], and is not confined to 2D but exists also in 3D [27]. It has also been proposed to described the physics of high-T c cuprates [28].…”