Related papers: Odd-frequency superfluidity from a particle-number…
The fermion Cooper pairing with unequal masses is investigated in a standard field theory approach. We derived the superfluid density and Meissner mass squared of the U(1) gauge field in a general two species model and found that the often…
We show that spontaneous time-reversal-symmetry (TRS) breaking can naturally arise from the interplay between pair density wave (PDW) ordering at multiple momenta and nesting of Fermi surfaces (FS). Concretely, we consider pair-density-wave…
We present a microscopic theory of fluctuation-mediated pairing mechanism in a two-dimensional extended Hubbard model. In contrast to conventional wisdom, odd-frequency spin-triplet pairing can be stabilized near the spin-density-wave…
We demonstrate that, quite generally, the spin-singlet even-parity (spin-triplet odd-parity) pair potential in a superconductor induces the odd-frequency pairing component with spin-singlet odd-parity (spin-triplet even-parity) near…
In this chapter we review recent experimental and theoretical work on various novel superfluid phases in fermion systems, that result from pairing fermions of different species with unequal densities. After briefly reviewing existing…
Superconductivity is characterized by a nonvanishing superconducting pair amplitude. It has a definite symmetry in spin, momentum and frequency (time). While the spin and momentum symmetry have been probed experimentally for different…
Majorana fermions are rising as a promising key component in quantum computation. While the prevalent approach is to use a quadratic (i.e. non-interacting) Majorana Hamiltonian, when expressed in terms of Dirac fermions, generically the…
We study two-species fermion gases with attractive interaction in two-dimensional optical lattices producing an array of elongated tube confinements. Focusing on the interplay of Cooper pairing, spin imbalance (or magnetization) and…
Superfluidity in fermionic systems originates from pairing of fermions, and Bose condensation of these so-called Cooper pairs. The Cooper pairs are usually made of fermions of different species; for example in superconductors they are pairs…
In several members of the pnictide materials, spin density wave order coexists with superconductivity over a range of dopings and temperature. In this paper we show that odd-frequency superconductivity emerges on the edges of pnictides in…
In this paper, we investigate the relation between odd-frequency pairing and proximity effect in non-uniform Kitaev chain systems with a particular interest in the topological critical point. First, we correlate the odd-frequency pairing…
We extend our recent work [Y. Endo et. al., Phys. Rev. 92, 023610 (2015)] for a parity-mixing effect in a model two-dimensional lattice fermions to a realistic three-dimensional ultracold Fermi gas. Including effects of broken local spatial…
Recent experiments have observed condensation behavior in a strongly interacting system of fermionic atoms. We interpret these observations in terms of a mean-field version of resonance superfluidity theory. We find that the objects…
The condensation of fermion pairs lies at the heart of superfluidity. However, for strongly correlated systems with reduced dimensionality the mechanisms of pairing and condensation are still not fully understood. In our experiment we use…
An equal time version of odd-frequency pairing for a generalized $t-J$ model is introduced. It is shown that the composite operators describing binding of Cooper pairs with magnetization fluctuations naturally appear in this approach. The…
We revisit the question of nature of odd-frequency superconductors, first proposed by Berezinskii in 1974. \cite{berezinskii1974} We start with the notion that order parameter of odd-frequency superconductors can be thought of as a time…
This article reviews odd-frequency (odd-w) pairing with focus on superconducting systems. Since Berezinskii introduced the concept of odd frequency order in 1974 it has been viewed as an exotic and rarely occurring in nature. Here, we…
The dc Josephson effect provides a powerful phase-sensitive tool for investigating superfluid order parameters. We report on the observation of dc Josephson supercurrents in strongly interacting fermionic superfluids across a tunnelling…
We consider physical properties of a superconductor with a recently proposed type of odd-frequency pairing that exhibits diamagnetic Meissner response ("odd-dia state"). Such a state was suggested in order to address stability issues…
We offer strong evidence that the recent observations by M. Greiner, C. Regal, and D. Jin and by MIT group are signatures of a fermion superfluid in the strongly interacting regime made up of large fermion pairs. Our conclusions are based…