Suk Bum Chung

Detecting the Majorana fermion surface state of 3He-B through spin relaxation.

The Majorana fermion, which can be useful for topological quantum computation, has eluded detection. (3)He-B, recently shown to be a time-reversal invariant topological superfluid, has a gapless Majorana fermion surface state. We show here that an electron spin relaxation experiment can detect this surface state--its Majorana nature through the Zeeman field direction dependence of the relaxation time 1/T(1) proportional, proportional to sin(2)theta, where theta is the angle between the field and the surface normal. We propose an experimental setup where an electron inside a nanobubble is injected below the (3)He liquid surface.

Phase, grain structure, stress, and resistivity of sputter-deposited tungsten films

Sputter-deposited W films with nominal thicknesses between 5 and 180 nm were prepared by varying the base pressure prior to film deposition and by including or not including sputtered SiO2 encapsulation layers. X-ray and electron diffraction studies showed that single phase, polycrystalline α-W could be achieved in as-deposited films as thin as 5 nm. The stress state in the as-deposited films was found to be inhomogeneous. Annealing resulted in stress relaxation and reduction of resistivity for all films, except the thinnest, unencapsulated film, which agglomerated. In-plane film grain sizes measured for a subset of the annealed films with thicknesses between 5 and 180 nm surprisingly showed a near constant value (101–116 nm), independent of film thickness. Thick-film (≥120 nm) resistivity values as low as 8.6 μΩ cm at 301 K were obtained after annealing at 850 °C for 2 h. Film resistivities were found to increase with decreasing film thicknesses below 120 nm, even for films which are fully A2 α-W with no metastable, A15 β-W evident. Sputter-deposited W films with nominal thicknesses between 5 and 180 nm were prepared by varying the base pressure prior to film deposition and by including or not including sputtered SiO2 encapsulation layers. X-ray and electron diffraction studies showed that single phase, polycrystalline α-W could be achieved in as-deposited films as thin as 5 nm. The stress state in the as-deposited films was found to be inhomogeneous. Annealing resulted in stress relaxation and reduction of resistivity for all films, except the thinnest, unencapsulated film, which agglomerated. In-plane film grain sizes measured for a subset of the annealed films with thicknesses between 5 and 180 nm surprisingly showed a near constant value (101–116 nm), independent of film thickness. Thick-film (≥120 nm) resistivity values as low as 8.6 μΩ cm at 301 K were obtained after annealing at 850 °C for 2 h. Film resistivities were found to increase with decreasing film thicknesses below 120 nm, even for films which are fully A2 α-W with no...

Stability of half-quantum vortices in px + ipy superconductors

We consider the stability conditions for half-quantum vortices in a quasi-two-dimensional p{x}+ip{y} superconductor (such as Sr2RuO4 is believed to be). The predicted exotic nature of these excitations has recently attracted much attention, but they have not been observed yet. We emphasize that an isolated half-quantum vortex has a divergent energy cost in the bulk due to its unscreened spin current, which requires two half-quantum vortices with opposite spin winding to pair. We show that the stability of such a pair is enhanced when the ratio of spin superfluid density to superfluid density rho{sp}/rho{s} is small. We propose using various mesoscopic geometries to stabilize and observe these exotic excitations.

Topological superconducting phase and Majorana fermions in half-metal/superconductor heterostructures

As a half-metal is spin polarized at its Fermi level by definition, it was conventionally thought to have little proximity effect to an

Majorana zero modes in a quantum Ising chain with longer-ranged interactions

s

Conductance and noise signatures of Majorana backscattering

-wave superconductor. Here we show that with interface spin-orbit coupling

Weak antilocalization and linear magnetoresistance in the surface state of SmB 6

{p}_{x}+i{p}_{y}

Time-reversal anomaly and Josephson effect in time-reversal invariant topological superconductors

superconductivity without spin degeneracy is induced on the half-metal, and we give an estimate of its bulk energy gap. Therefore, a single-band half-metal can give us a topological superconductor with a single chiral Majorana edge state. Our band calculation shows that two atomic layers of VTe or CrO

Charge and spin collective modes in a quasi-one-dimensional model of Sr2RuO4

{}_{2}

Proposal for reading out anyon qubits in non-Abelian v=12/5 quantum Hall state

is a single-band half-metal for a wide range (