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Periportal Capsulotomy: A Technique for Limited Violation of the Hip Capsule During Arthroscopy for Femoroacetabular Impingement.
Hip arthroscopy has become the standard treatment for symptomatic femoroacetabular impingement as patients have shown good outcomes and high satisfaction with this intervention. However, capsular management to gain access for intra-articular procedures remains greatly debated. Capsular closure is advocated particularly in the setting of interportal or T-capsulotomy to avoid complications of instability or nonhealing capsule. We introduce a technique for capsular management through a limited periportal capsulotomy during arthroscopic treatment of femoroacetabular impingement. In using dilation of the anterolateral and mid-anterior portals without completion of a full interportal capsulotomy, the stabilizing iliofemoral ligament is preserved. We have found that periportal capsulotomy provides safe and sufficient access to the hip joint without necessitating capsular closure
Experimental Bell Inequality Violation with an Atom and a Photon
We report the measurement of a Bell inequality violation with a single atom
and a single photon prepared in a probabilistic entangled state. This is the
first demonstration of such a violation with particles of different species.
The entanglement characterization of this hybrid system may also be useful in
quantum information applications.Comment: 4 pages, 2 figure
Trapped ion quantum computation with transverse phonon modes
We propose a scheme to implement quantum gates on any pair of trapped ions
immersed in a large linear crystal, using interaction mediated by the
transverse phonon modes. Compared with the conventional approaches based on the
longitudinal phonon modes, this scheme is much less sensitive to ion heating
and thermal motion outside of the Lamb-Dicke limit thanks to the stronger
confinement in the transverse direction. The cost for such a gain is only a
moderate increase of the laser power to achieve the same gate speed. We also
show how to realize arbitrary-speed quantum gates with transverse phonon modes
based on simple shaping of the laser pulses.Comment: 5 page
Scaling and Suppression of Anomalous Heating in Ion Traps
We measure and characterize anomalous motional heating of an atomic ion confined in the lowest quantum levels of a novel rf ion trap that features moveable electrodes. The scaling of heating with electrode proximity is measured, and when the electrodes are cooled from 300 to 150 K, the heating rate is suppressed by an order of magnitude. This provides direct evidence that anomalous motional heating of trapped ions stems from microscopic noisy potentials on the electrodes that are thermally driven. These observations are relevant to decoherence in quantum information processing schemes based on trapped ions and perhaps other charge-based quantum systems
Arbitrary-speed quantum gates within large ion crystals through minimum control of laser beams
We propose a scheme to implement arbitrary-speed quantum entangling gates on
two trapped ions immersed in a large linear crystal of ions, with minimal
control of laser beams. For gate speeds slower than the oscillation frequencies
in the trap, a single appropriately-detuned laser pulse is sufficient for
high-fidelity gates. For gate speeds comparable to or faster than the local ion
oscillation frequency, we discover a five-pulse protocol that exploits only the
local phonon modes. This points to a method for efficiently scaling the ion
trap quantum computer without shuttling ions.Comment: 4 page
The Solar Twin Planet Search II. A Jupiter twin around a solar twin
Through our HARPS radial velocity survey for planets around solar twin stars,
we have identified a promising Jupiter twin candidate around the star HIP11915.
We characterize this Keplerian signal and investigate its potential origins in
stellar activity. Our analysis indicates that HIP11915 hosts a Jupiter-mass
planet with a 3800-day orbital period and low eccentricity. Although we cannot
definitively rule out an activity cycle interpretation, we find that a planet
interpretation is more likely based on a joint analysis of RV and activity
index data. The challenges of long-period radial velocity signals addressed in
this paper are critical for the ongoing discovery of Jupiter-like exoplanets.
If planetary in nature, the signal investigated here represents a very close
analog to the solar system in terms of both Sun-like host star and Jupiter-like
planet.Comment: 8 pages, 5 figures; A&A accepted; typos corrected in this versio
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