Electron transport through [normal metal]-[quantum dot]-[topological superconductor] junction is studied and reveals interlacing physics of Kondo correlations with two Majorana fermions bound state residing on the opposite edges of the topological superconductor. When the strength of the Majorana fermion coupling exceeds the temperature T , this combination of Kono-Majorana fermion physics can be observed: The usual peak of the temperature dependent zero biased conductance σ(V = 0, T ) splits and the conductance has a dip at T = 0. The height of the conductance side-peaks decreases with magnetic field.
We consider the easy-plane anisotropic spin-Heisenberg chain in combined uniform longitudinal and transverse staggered magnetic fields. The low-energy limit of his model is described by the sineGordon quantum field theory. Using methods of integrable quantum field theory we determine the various components of the dynamical structure factor. To do so, we derive explicit expressions for all matrix elements of the low-energy projections of the spin operators involving at most two particles. We discuss applications of our results to experiments on one-dimensional quantum magnets.
In a cold atom gas subject to a 2D spin-dependent optical lattice potential with hexagonal symmetry, trapped atoms execute circular motion around the potential minima. Such atoms are elementary quantum rotors. The theory of such quantum rotors is developed. Wave functions, energies, and degeneracies are determined for both bosonic and fermionic atoms, and magnetic dipole transitions between quantum rotor states are elucidated. Quantum rotors in optical lattices with precisely one atom per unit cell can be used as extremely high sensitivity rotation sensors, accelerometers, and magnetometers.
The feasibility of realizing overscreened Kondo effect in ultra-cold Fermi gas of atoms with spin s ≥ 3 2 in the presence of a localized magnetic impurity atom is proved realistic. Specifying (as a mere example), to a system of ultra cold 22 Na Fermi gas and a trapped 197 Au impurity, the mechanism of exchange interaction between the Na and Au atoms is elucidated and the exchange constant is found to be positive (antiferromagnetic). The corresponding exchange Hamiltonian is derived, and the Kondo temperature is estimated at the order of 1 µK. Within a weak-coupling renormalization group scheme, it is shown that the coupling renormalizes to the non-Fermi liquid fixed point. An observable displaying multi-channel features even in the weak coupling regime is the impurity magnetization: For T ≫ TK it is negative, and then it increases to become positive with decreasing temperature.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.