Controlling fast transport of cold trapped ions

We realize fast transport of ions in a segmented micro-structured Paul trap. The ion is shuttled over a distance of more than 10^4 times its groundstate wavefunction size during only 5 motional cycles of the trap (280 micro meter in 3.6 micro seconds). Starting from a ground-state-cooled ion, we find an optimized transport such that the energy increase is as low as 0.10 $\pm$ 0.01 motional quanta. In addition, we demonstrate that quantum information stored in a spin-motion entangled state is preserved throughout the transport. Shuttling operations are concatenated, as a proof-of-principle for the shuttling-based architecture to scalable ion trap quantum computing.Comment: 5 pages, 4 figure

Reliability and Validity of a Clinical Assessment Tool for Measuring Scapular Motion in All 3 Anatomical Planes

CONTEXT: A single clinical assessment device that objectively measures scapular motion in each anatomical plane is not currently available. The development of a novel electric goniometer affords the ability to quantify scapular motion in all three anatomical planes. OBJECTIVE: Investigate the reliability and validity of an electric goniometer to measure scapular motion in each anatomical plane during arm elevation. DESIGN: Cross-sectional. SETTING: Laboratory setting. PATIENTS OR OTHER PARTICIPANTS: Sixty participants (29 females, 31 males) were recruited from the general population. INTERVENTION(S): An electric goniometer was used to record clinical measurements of scapular position at rest and total arc of motion (excursion) during active arm elevation in two testing sessions separated by several days. Measurements were recorded independently by two examiners. In one session, scapular motion was recorded simultaneously with a 14-camera three-dimensional optical motion capture system. MAIN OUTCOME MEASURES: Reliability analysis included examination of clinical measurements for scapular position at rest and excursion during each condition. Both the intra-rater reliability between testing sessions and the inter-rater reliability recorded within the same session were assessed using Intraclass Correlation Coefficients (ICC2,3). The criterion-validity was examined by comparing the mean excursion values of each condition recorded by the electric goniometer to the 3D optical motion capture system. Validity was assessed by evaluating the average difference and root mean square error (RMSE). RESULTS: The between session intra-rater reliability was moderate to good (ICC2,3: 0.628-0.874). The within session inter-rater reliability was moderate to excellent (ICC2,3: 0.545-0.912). The average difference between the electric goniometer and 3D optical motion capture system ranged from -7° to 4° and the RMSE was between 7-10°. CONCLUSIONS: The reliability of scapular measurements is best when a standard operating procedure is used. The electric goniometer provides an accurate measurement of scapular excursions in all three anatomical planes during arm elevation

Cryogenic platform for coupling color centers in diamond membranes to a fiber-based microcavity

We operate a fiber-based cavity with an inserted diamond membrane containing ensembles of silicon vacancy centers (SiV$^{-}$) at cryogenic temperatures ≥4 K. The setup, sample fabrication and spectroscopic characterization are described, together with a demonstration of the cavity influence by the Purcell effect. This paves the way towards solid-state qubits coupled to optical interfaces as long-lived quantum memories

Cryogenic platform for coupling color centers in diamond membranes to a fiberbased microcavity

We operate a fiberbased cavity with an inserted diamond membrane containing ensembles of silicon vacancy centers (SiV$^-$) at cryogenic temperatures $\geq4~$K. The setup, sample fabrication and spectroscopic characterization is described, together with a demonstration of the cavity influence by the Purcell effect. This paves the way towards solid state qubits coupled to optical interfaces as long-lived quantum memories.Comment: 10 pages, 6 figure

The Prevalence and Clinical Implications of Comorbid Back Pain in Shoulder Instability: A Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Cohort Study.

Background:Understanding predictors of pain is critical, as recent literature shows that comorbid back pain is an independent risk factor for worse functional and patient-reported outcomes (PROs) as well as increased opioid dependence after total joint arthroplasty. Purpose/Hypothesis:The purpose of this study was to evaluate whether comorbid back pain would be predictive of pain or self-reported instability symptoms at the time of stabilization surgery. We hypothesized that comorbid back pain will correlate with increased pain at the time of surgery as well as with worse scores on shoulder-related PRO measures. Study Design:Cross-sectional study; Level of evidence, 3. Methods:As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients consented to participate in pre- and intraoperative data collection. Demographic characteristics, injury history, preoperative PRO scores, and radiologic and intraoperative findings were recorded for patients undergoing surgical shoulder stabilization. Patients were also asked, whether they had any back pain. Results:The study cohort consisted of 1001 patients (81% male; mean age, 24.1 years). Patients with comorbid back pain (158 patients; 15.8%) were significantly older (28.1 vs 23.4 years; P < .001) and were more likely to be female (25.3% vs 17.4%; P = .02) but did not differ in terms of either preoperative imaging or intraoperative findings. Patients with self-reported back pain had significantly worse preoperative pain and shoulder-related PRO scores (American Shoulder and Elbow Surgeons score, Western Ontario Shoulder Instability Index) (P < .001), more frequent depression (22.2% vs 8.3%; P < .001), poorer mental health status (worse scores for the RAND 36-Item Health Survey Mental Component Score, Iowa Quick Screen, and Personality Assessment Screener) (P < .01), and worse preoperative expectations (P < .01). Conclusion:Despite having similar physical findings, patients with comorbid back pain had more severe preoperative pain and self-reported symptoms of instability as well as more frequent depression and lower mental health scores. The combination of disproportionate shoulder pain, comorbid back pain and mental health conditions, and inferior preoperative expectations may affect not only the patient's preoperative state but also postoperative pain control and/or postoperative outcomes

Coherent Manipulation of a Ca Spin Qubit in a Micro Ion Trap

We demonstrate the implementation of a spin qubit with a single Ca ion in a micro ion trap. The qubit is encoded in the Zeeman ground state levels mJ=+1/2 and mJ=-1/2 of the S1/2 state of the ion. We show sideband cooling close to the vibrational ground state and demonstrate the initialization and readout of the qubit levels with 99.5% efficiency. We employ a Raman transition close to the S1/2 - P1/2 resonance for coherent manipulation of the qubit. We observe single qubit rotations with 96% fidelity and gate times below 5mus. Rabi oscillations on the blue motional sideband are used to extract the phonon number distribution. The dynamics of this distribution is analyzed to deduce the trap-induced heating rate of 0.3(1) phonons/ms