8,444 research outputs found
Outgassing measurement of the aluminum alloy UHV chamber
A large vacuum chamber (580 mm diameter) was fabricated from an aluminum alloy surface treated by a special process normally used on small chambers. The chamber was tested unbaked and baked at various temperatures, pressures, and holding periods. The chamber was filled with N2 gas, and the outgassing rate was measured after one hour. Then the ultimate pressure was measured. Outgassing rates for baked and unbaked groups were compared. It is concluded that the same surface treatment technique can be used on both large and small chambers produced by the same special extrusion process
Unoccupied topological surface state in BiTeSe
Bias voltage dependent scattering of the topological surface state is studied
by scanning tunneling microscopy/spectroscopy for a clean surface of the
topological insulator BiTeSe. A strong warping of constant energy
contours in the unoccupied part of the spectrum is found to lead to a
spin-selective scattering. The topological surface state persists to higher
energies in the unoccupied range far beyond the Dirac point, where it coexists
with the bulk conduction band. This finding sheds light on the spin and charge
dynamics over the wide energy range and opens a way to designing
opto-spintronic devices.Comment: 5 pages, 4 figure
The effects of Zn Impurity on the Properties of Doped Cuprates in the Normal State
We study the interplay of quantum impurity, and collective spinon and holon
dynamics in Zn doped high-T cuprates in the normal state. The
two-dimensional t-t-J models with one and a small amount of Zn
impurity are investigated within a numerical method based on the double-time
Green function theory. We study the inhomogeneities of holon density and
antiferromagnetic correlation background in cases with different Zn
concentrations, and obtain that doped holes tend to assemble around the Zn
impurity with their mobility being reduced. Therefore a bound state of holon is
formed around the nonmagnetic Zn impurity with the effect helping Zn to
introduce local antiferromagnetism around itself. The incommensurate peaks we
obtained in the spin structure factor indicate that Zn impurities have effects
on mixing the q=(, ) and q=0 components in spin excitations.Comment: 5 pages, 3 figure
Arthroscopic management of temporomandibular closed lock
The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included
Surface Scattering via Bulk Continuum States in the 3D Topological Insulator BiSe
We have performed scanning tunneling microscopy and differential tunneling
conductance () mapping for the surface of the three dimensional
topological insulator BiSe. The fast Fourier transformation applied
to the image shows an electron interference pattern near Dirac node
despite the general belief that the backscattering is well suppressed in the
bulk energy gap region. The comparison of the present experimental result with
theoretical surface and bulk band structures shows that the electron
interference occurs through the scattering between the surface states near the
Dirac node and the bulk continuum states.Comment: 5 pages, 4 figure
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