Optimal Jet Finder

We describe a FORTRAN 77 implementation of the optimal jet definition for identification of jets in hadronic final states of particle collisions. We discuss details of the implementation, explain interface subroutines and provide a usage example. The source code is available from http://www.inr.ac.ru/~ftkachov/projects/jets/Comment: version to appear in Comp. Phys. Commun., 36 page

Nonmetallic thermal transport in low-dimensional proximity structures with partially preserved time-reversal symmetry in a magnetic field

Gapped excitation spectra of Andreev states are studied in one- and two-dimensional (1D and 2D) normal systems in superconducting contacts subject to a parallel magnetic field. In the ballistic regime, a specific interplay between magnetic field spin splitting and the effect of a screening supercurrent is found to preserve time-reversal symmetry for certain groups of Andreev states remaining gapped despite the presense of the magnetic field. In 1D wires such states can lead to a fractional thermal magnetoconductance equal to half of the thermal conductance quantum. In 2D systems the thermal magnetoconductance is also predicted to remain suppressed well below the normal-state value in a wide range of magnetic fields.Comment: 21 pages, 7 figure

Dirac fermion quantization on graphene edges: Isospin-orbit coupling, zero modes and spontaneous valley polarization

The paper addresses boundary electronic properties of graphene with a complex edge structure of the armchair/zigzag/armchair type. It is shown that the finite zigzag region supports edge bound states with discrete equidistant spectrum obtained from the Green's function of the continuum Dirac equation. The energy levels exhibit the coupling between the valley degree of freedom and the orbital quantum number, analogous to a spin-orbit interaction. The characteristic feature of the spectrum is the presence of a zero mode, the bound state of vanishing energy. It resides only in one of the graphene valleys, breaking spontaneously Kramers' symmetry of the edge states. This implies the spontaneous valley polarization characterized by the valley isospin $\pm 1/2$. The polarization is manifested by a zero-magnetic field anomaly in the local tunneling density of states, and is directly related to the local electric Hall conductivity.Comment: 9 pages, 6 figures, to be published in Phys. Rev.

Weak localization and Berry flux in topological crystalline insulators with a quadratic surface spectrum

The paper examines weak localization (WL) of surface states with a quadratic band crossing in topological crystalline insulators. It is shown that the topology of the quadratic band crossing point dictates the negative sign of the WL conductivity correction. For the surface states with broken time-reversal symmetry, an explicit dependence of the WL conductivity on the band Berry flux is obtained and analyzed for different carrier-density regimes and types of the band structure (normal or inverted). These results suggest a way to detect the band Berry flux through WL measurements.Comment: 7.2 pages, 5 figures, 1 reference and 2 footnotes adde