49,308 research outputs found
Short time relaxation of a driven elastic string in a random medium
We study numerically the relaxation of a driven elastic string in a two
dimensional pinning landscape. The relaxation of the string, initially flat, is
governed by a growing length separating the short steady-state
equilibrated lengthscales, from the large lengthscales that keep memory of the
initial condition. We find a macroscopic short time regime where relaxation is
universal, both above and below the depinning threshold, different from the one
expected for standard critical phenomena. Below the threshold, the zero
temperature relaxation towards the first pinned configuration provides a novel,
experimentally convenient way to access all the critical exponents of the
depinning transition independently.Comment: 4.2 pages, 3 figure
Electric Field Effect in Diluted Magnetic Insulator Anatase Co:TiO2
An external electric field induced reversible modulation of room temperature
magnetic moment is achieved in an epitaxial and insulating thin film of
dilutely cobalt-doped anatase TiO2. This first demonstration of electric field
effect in any oxide based diluted ferromagnet is realized in a high quality
epitaxial heterostructure of PbZr0.2Ti0.8O3/Co:TiO2/SrRuO3 grown on (001)
LaAlO3. The observed effect, which is about 15% in strength in a given
heterostructure, can be modulated over several cycles. Possible mechanisms for
electric field induced modulation of insulating ferromagnetism are discussed.Comment: 14 pages, 4 figure
Optical spectroscopy study on CeTe: evidence for multiple charge-density-wave orders
We performed optical spectroscopy measurement on single crystal of CeTe,
a rare-earth element tri-telluride charge density wave (CDW) compound. The
optical spectra are found to display very strong temperature dependence.
Besides a large and pronounced CDW energy gap being present already at room
temperature as observed in earlier studies, the present measurement revealed
the formation of another energy gap at smaller energy scale at low temperature.
The second CDW gap removes the electrons near E which undergo stronger
scattering. The study yields evidence for the presence of multiple CDW orders
or strong fluctuations in the light rare-earth element tri-telluride.Comment: 5 figure
Strongly Secure and Efficient Data Shuffle On Hardware Enclaves
Mitigating memory-access attacks on the Intel SGX architecture is an
important and open research problem. A natural notion of the mitigation is
cache-miss obliviousness which requires the cache-misses emitted during an
enclave execution are oblivious to sensitive data. This work realizes the
cache-miss obliviousness for the computation of data shuffling. The proposed
approach is to software-engineer the oblivious algorithm of Melbourne shuffle
on the Intel SGX/TSX architecture, where the Transaction Synchronization
eXtension (TSX) is (ab)used to detect the occurrence of cache misses. In the
system building, we propose software techniques to prefetch memory data prior
to the TSX transaction to defend the physical bus-tapping attacks. Our
evaluation based on real implementation shows that our system achieves superior
performance and lower transaction abort rate than the related work in the
existing literature.Comment: Systex'1
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