327 research outputs found
Ion traps fabricated in a CMOS foundry
We demonstrate trapping in a surface-electrode ion trap fabricated in a 90-nm
CMOS (complementary metal-oxide-semiconductor) foundry process utilizing the
top metal layer of the process for the trap electrodes. The process includes
doped active regions and metal interconnect layers, allowing for co-fabrication
of standard CMOS circuitry as well as devices for optical control and
measurement. With one of the interconnect layers defining a ground plane
between the trap electrode layer and the p-type doped silicon substrate, ion
loading is robust and trapping is stable. We measure a motional heating rate
comparable to those seen in surface-electrode traps of similar size. This is
the first demonstration of scalable quantum computing hardware, in any
modality, utilizing a commercial CMOS process, and it opens the door to
integration and co-fabrication of electronics and photonics for large-scale
quantum processing in trapped-ion arrays.Comment: 4 pages, 3 figure
Precision measurement of the 5 2S1/2 - 4 2D5/2 quadrupole transition isotope shift between 88Sr+ and 86Sr+
We have measured the isotope shift of the narrow quadrupole-allowed 5 2S1/2 -
4 2D5/2 transition in 86Sr+ relative to the most abundant isotope 88Sr+. This
was accomplished using high-resolution laser spectroscopy of individual trapped
ions, and the measured shift is Delta-nu_meas^(88,86) = 570.281(4) MHz. We have
also tested a recently developed and successful method for ab-initio
calculation of isotope shifts in alkali-like atomic systems against this
measurement, and our initial result of Delta-nu_calc^(88,86) = 457(28) MHz is
also presented. To our knowledge, this is the first high precision measurement
and calculation of that isotope shift. While the measurement and the
calculation are in broad agreement, there is a clear discrepancy between them,
and we believe that the specific mass shift was underestimated in our
calculation. Our measurement provides a stringent test for further refinements
of theoretical isotope shift calculation methods for atomic systems with a
single valence electron
Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors
An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide an engineering technology base for development of large scale hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed for conducting experimental investigations. Oxidizer (LOX or GOX) is injected through the head-end over a solid fuel (HTPB) surface. Experiments using fuels supplied by NASA designated industrial companies will also be conducted. The study focuses on the following areas: measurement and observation of solid fuel burning with LOX or GOX, correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study also being conducted at PSU
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