We show that one-dimensional electron systems in the proximity of a superconductor that support Majorana edge states are extremely susceptible to electron-electron interactions. Strong interactions generically destroy the induced superconducting gap that stabilizes the Majorana edge states. For weak interactions, the renormalization of the gap is nonuniversal and allows for a regime in which th...

The theoretical basics of neutrino mass and mixing are reviewed. Dirac and Majorana masses are explained, and added together to produce the see-saw picture of the lightness of neutrinos. This picture predicts that neutrinos are Majorana particles. The character, and an apparent paradox, of Majorana neutrinos are examined. The physics of neutrino flavor change (oscillation), in vacuo and in matt...

Axions (in the general sense) may acquire qualitatively new couplings inside superfluids. Their conventional couplings to fermions, in empty space, involve purely imaginary masses; the new couplings involve emergent Majorana masses. A generalized concept of Majorana mass is proposed, which allows continuous interpolation between Majorana and Dirac fermions, and also extension to bosons. The pos...

We present a formalism that extends the Majorana-construction to arbitrary spin (j, 0)⊕(0, j) representation spaces. For the example case of spin-1, a wave equation satisfied by the Majorana-like (1, 0) ⊕ (0, 1) spinors is constructed and its physical content explored. The (j, 0) ⊕ (0, j) Majorana-construct is found to possess an unusual classical and quantum field theoretic structure. Relevanc...

The irreducibility of a representation of a real Lie algebra may depend on whether the representation space is a real or complex Hilbert space. The unitary projective representations of the Poincare group on complex Hilbert spaces were studied by Wigner and many others. Although the Poincare group has a real Lie algebra, we do not know of any study of the orthogonal projective representations o...

Majorana fermions are quasiparticle excitations which are features of a two-dimensional quantum system in a so-called topological phase. Majorana fermions are non-Abelian anyons and the system therefore has a degenerate groundstate protected by a gap to the other excitations. It has been proposed that a system with Majorana fermions can be utilized for performing fault-tolerant quantum computat...

One Majorana doublet can be realized at each end of the time-reversal-invariant Majorana nanowires. We investigate the Josephson effect in the Majorana-doublet-presented junction modified by different inter-doublet coupling manners. It is found that when the Majorana doublets couple indirectly via a non-magnetic quantum dot, only the normal Josephson effect occurs, and the fermion parity in the...

Green-Schwarz action of Type IIB string on AdS3 × S is constructed via coset superspace approach. The construction relies exclusively on symplectically Majorana-Weyl spinor formalism, thus permitting it easier to prove κ-symmetry for on-shell Type IIB supergravity backgrounds. 1 Work supported in part by the U.S. Department of Energy under Grant No. DE-FG02-90-ER40542, KOSEF Interdisciplinary R...

Majorana fermion (MF) excitations in solid state system have non-Abelian statistics which is essential for topological quantum computation. Previous proposals to realize MF, however, generally requires fine-tuning of parameters. Here we explore a platform which avoids the fine-tuning problem, namely a ferromagnetic chain deposited on the surface of a spin-orbit coupled s-wave superconductor. We...

Recent experimental efforts towards the detection of Majorana bound states have focused on creating the conditions for topological superconductivity. Here we demonstrate an alternative route, which achieves fully localised zero-energy Majorana bound states when a topologically trivial superconductor is strongly coupled to a helical normal region. Such a junction can be experimentally realised b...