Related papers: Collective modes in two dimensional topological su…
The equations of motion of pair-like excitations in the superconducting state are studied for various types of pairing using the random phase approximation. The collective modes are computed of a layered electron gas described by a $t-t'$…
We analyze collective modes in two-band superconductors in the dirty limit. It is shown that these modes exist at all temperatures $T$ below $T_{c}$ provided the frequency of the modes is higher than the inelastic scattering rate and lower…
The $j = 3/2$ fermions in cubic crystals or cold atomic gases can form Cooper pairs in both singlet ($J = 0$) and unconventional quintet ($J = 2$) $s$-wave states. Our study utilizes analytical field theory to examine fluctuations in these…
It is interesting to ask whether electron interaction can turn a topologically trivial superconductor into a nontrivial one without the presence of spin-obital coupling. In this paper we solve a correlated $s$-wave superconducting model…
At the first glance, the expression "transparent superconductor" may seem an oxymoron. Still, the first principle calculations and experiments show that the materials that behave as superconductors at low frequencies and do not absorb in…
Unconventional superconductors have been long sought for their potential applications in quantum technologies and devices. A key challenge impeding this effort is the difficulty associated with probing and characterizing candidate materials…
A high-energy spin resonance mode is known to exist in many high-temperature superconductors. Motivated by recent scanning tunneling microscopy (STM) experiments in superconducting Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$, we study the effects of…
Emergence of odd-frequency s-wave superconductivity is demonstrated in the two-channel Kondo lattice by means of the dynamical mean-field theory combined with the continuous-time quantum Monte Carlo method. Around half filling of the…
Motivated by the recent observations of nodeless superconductivity in the monolayer CuO$_{2}$ grown on the Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta }$ substrates, we study the two-dimensional superconducting (SC) phases described by the…
The energy, momentum and temperature dependence of the quasiparticle local density of states (LDOS) of a two-dimensional $d_{x^2-y^2}$-wave superconductor with random disorder is investigated using the first-order T-matrix approximation.…
Collective, low-energy excitations in quasi-two-dimensional d-wave superconductors are analyzed. While the long-range Coulomb interaction shifts the charge-density-wave and phase modes up to the plasma energy, the spin-density-wave…
When a continuous symmetry of a physical system is spontaneously broken, two types of collective modes typically emerge: the amplitude and phase modes of the order-parameter fluctuation. For superconductors, the amplitude mode is recently…
We investigate the three-dimensional, time-reversal invariant topological superconductors with generic interaction by their response to external fields. The first description is a gravitational topological field theory, which gives a $Z_2$…
We calculate the collective mode spectrum in models of superconductors with attractive interactions in s-and d channels as a function of their relative strength, across a phase diagram that includes transition between s, s+id, and d-wave…
Standard weak coupling methods are used to study collective modes in the superconducting state of a double-layer system with intralayer and interlayer interaction, as well as a Josephson-type coupling and single particle hopping between the…
The collective mode spectrum of a symmetry-breaking state, such as a superconductor, provides crucial insight into the nature of the order parameter. In this context, we present a microscopic weak-coupling theory for the collective modes of…
We investigate numerically the signatures of collective modes in the tunneling spectra of superconductors. The larger strength of the signatures observed in the high-Tc superconductors, as compared to classical low-Tc materials, is…
Topological superconductors are gapped superconductors with gapless and topologically robust quasiparticles propagating on the boundary. In this paper, we present a topological field theory description of three-dimensional time-reversal…
Taking account of a collective mode relevant to charge fluctuation, the optical conductivity of spin-density-wave state has been examined for an extended Hubbard model with one-dimensional quarter-filled band. We find that, within the…
Molecular dynamics simulations have been performed to investigate in detail collective modes spectra of two-dimensional Coulomb fluids in a wide range of coupling. The obtained dispersion relations are compared with theoretical approaches…