331 research outputs found
Optimal Phonon-to-Spin Mapping in a system of a trapped ion
We propose a protocol for measurement of the phonon number distribution of a
harmonic oscillator based on selective mapping to a discrete spin-1/2 degree of
freedom. We consider a system of a harmonically trapped ion, where a transition
between two long lived states can be driven with resolved motional sidebands.
The required unitary transforms are generated by amplitude-modulated
polychromatic radiation fields, where the time-domain ramps are obtained from
numerical optimization by application of the Chopped RAndom Basis (CRAB)
algorithm. We provide a detailed analysis of the scaling behavior of the
attainable fidelities and required times for the mapping transform with respect
to the size of the Hilbert space. As one application we show how the mapping
can be employed as a building block for experiments which require measurement
of the work distribution of a quantum process
Software Grand Exposure: SGX Cache Attacks Are Practical
Side-channel information leakage is a known limitation of SGX. Researchers
have demonstrated that secret-dependent information can be extracted from
enclave execution through page-fault access patterns. Consequently, various
recent research efforts are actively seeking countermeasures to SGX
side-channel attacks. It is widely assumed that SGX may be vulnerable to other
side channels, such as cache access pattern monitoring, as well. However, prior
to our work, the practicality and the extent of such information leakage was
not studied.
In this paper we demonstrate that cache-based attacks are indeed a serious
threat to the confidentiality of SGX-protected programs. Our goal was to design
an attack that is hard to mitigate using known defenses, and therefore we mount
our attack without interrupting enclave execution. This approach has major
technical challenges, since the existing cache monitoring techniques experience
significant noise if the victim process is not interrupted. We designed and
implemented novel attack techniques to reduce this noise by leveraging the
capabilities of the privileged adversary. Our attacks are able to recover
confidential information from SGX enclaves, which we illustrate in two example
cases: extraction of an entire RSA-2048 key during RSA decryption, and
detection of specific human genome sequences during genomic indexing. We show
that our attacks are more effective than previous cache attacks and harder to
mitigate than previous SGX side-channel attacks
Operation of a Microfabricated Planar Ion-Trap for Studies of a Yb-Rb Hybrid Quantum System
In order to study interactions of atomic ions with ultracold neutral atoms,
it is important to have sub-m control over positioning ion crystals.
Serving for this purpose, we introduce a microfabricated planar ion trap
featuring 21 DC electrodes. The ion trap is controlled by a home-made FPGA
voltage source providing independently variable voltages to each of the DC
electrodes. To assure stable positioning of ion crystals with respect to
trapped neutral atoms, we integrate into the overall design a compact mirror
magneto optical chip trap (mMOT) for cooling and confining neutral Rb
atoms. The trapped atoms will be transferred into an also integrated chipbased
Ioffe-Pritchard trap potential formed by a Z-shaped wire and an external bias
magnetic field.We introduce the hybrid atom-ion chip, the microfabricated
planar ion trap and use trapped ion crystals to determine ion lifetimes, trap
frequencies, positioning ions and the accuracy of the compensation of
micromotion.Comment: 10 pages, 13 figure
Kurzer Unterricht in der Erdbeschreibung und Geschichte : für Schulen und zum Selbstunterrichte
https://www.ester.ee/record=b4007293*es
Leichtfasslicher Unterricht im Rechnen, für Schulen und zur Selbstbelehrung
https://www.ester.ee/record=b4115918*es
Die Regulierung Künstlicher Intelligenz - Neuer Rechtsrahmen für Algorithmische Entscheidungssysteme?
Richard Löwenherz : Ballade von Wolfgang Müller von Königswinter für Chor, Tenorsolo und Orchester ; op. 200 / von Ferdinand Hiller
Lorelei : Gedicht von Wolfgang Müller von Königswinter ; für Solo-Stimmen, Chor und Orchester ; op. 70 / componirt von Ferdinand Hiller
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