743 research outputs found
Recent Developments: Agency—Respondeat Superior—Master\u27s Liability for the Intentional Torts of His Servant Committed within the Scope of Employment and in Furtherance of Master\u27s Business. Spence v. Newton, 20 Md. App. 126, 316 A.2d 837 (1974)
Effects of screened Coulomb impurities on autoionizing two-electron resonances in spherical quantum dots
In a recent paper (Phys. Rev. B {\bf 78}, 075316 (2008)), Sajeev and Moiseyev
demonstrated that the bound-to-resonant transitions and lifetimes of
autoionizing states in spherical quantum dots can be controlled by varying the
confinment strength. In the present paper, we report that such control can in
some cases be compromised by the presence of Coulomb impurities. It is
demonstrated that a screened Coulomb impurity placed in the vicinity of the dot
center can lead to bound-to-resonant transitions and to avoided crossings-like
behavior when the screening of the impurity charge is varied. It is argued that
these properties also can have impact on electron transport through quantum dot
arrays
Synesthesia: Detecting Screen Content via Remote Acoustic Side Channels
We show that subtle acoustic noises emanating from within computer screens
can be used to detect the content displayed on the screens. This sound can be
picked up by ordinary microphones built into webcams or screens, and is
inadvertently transmitted to other parties, e.g., during a videoconference call
or archived recordings. It can also be recorded by a smartphone or "smart
speaker" placed on a desk next to the screen, or from as far as 10 meters away
using a parabolic microphone.
Empirically demonstrating various attack scenarios, we show how this channel
can be used for real-time detection of on-screen text, or users' input into
on-screen virtual keyboards. We also demonstrate how an attacker can analyze
the audio received during video call (e.g., on Google Hangout) to infer whether
the other side is browsing the web in lieu of watching the video call, and
which web site is displayed on their screen
Recent Developments: Agency—Respondeat Superior—Master\u27s Liability for the Intentional Torts of His Servant Committed within the Scope of Employment and in Furtherance of Master\u27s Business. Spence v. Newton, 20 Md. App. 126, 316 A.2d 837 (1974)
Robustness of spatial Penning trap modes against environment-assisted entanglement
The separability of the spatial modes of a charged particle in a Penning trap
in the presence of an environment is studied by means of the positive partial
transpose (PPT) criterion. Assuming a weak Markovian environment, described by
linear Lindblad operators, our results strongly suggest that the environmental
coupling of the axial and cyclotron degrees of freedom does not lead to
entanglement at experimentally realistic temperatures. We therefore argue that,
apart from unavoidable decoherence, the presence of such an environment does
not alter the effectiveness of recently suggested quantum information protocols
in Penning traps, which are based on the combination of a spatial mode with the
spin of the particle.Comment: 11 pages, 2 figure
Non-Markovian Dynamics in Ultracold Rydberg Aggregates
We propose a setup of an open quantum system in which the environment can be
tuned such that either Markovian or non-Markovian system dynamics can be
achieved. The implementation uses ultracold Rydberg atoms, relying on their
strong long-range interactions. Our suggestion extends the features available
for quantum simulators of molecular systems employing Rydberg aggregates and
presents a new test bench for fundamental studies of the classification of
system-environment interactions and the resulting system dynamics in open
quantum systems.Comment: 13 pages, 4 figure
- …