1,382 research outputs found
Optimal Generators for Quantum Sensing
We propose a computationally efficient method to derive the unitary evolution
that a quantum state is most sensitive to. This allows one to determine the
optimal use of an entangled state for quantum sensing, even in complex systems
where intuition from canonical squeezing examples breaks down. In this paper we
show that the maximal obtainable sensitivity using a given quantum state is
determined by the largest eigenvalue of the quantum Fisher information matrix
(QFIM) and, importantly, the corresponding evolution is uniquely determined by
the coinciding eigenvector. Since we optimize the process of parameter encoding
rather than focusing on state preparation protocols, our scheme is relevant for
any quantum sensor. This procedure naturally optimizes multiparameter
estimation by determining, through the eigenvectors of the QFIM, the maximal
set of commuting observables with optimal sensitivity.Comment: 7 pages, 2 figure
A Machine-Designed Optical Lattice Atom Interferometer
Performing interferometry in an optical lattice formed by standing waves of
light offers potential advantages over its free-space equivalents since the
atoms can be confined and manipulated by the optical potential. We demonstrate
such an interferometer in a one dimensional lattice and show the ability to
control the atoms by imaging and reconstructing the wavefunction at many stages
during its cycle. An acceleration signal is applied and the resulting
performance is seen to be close to the optimum possible for the time-space area
enclosed according to quantum theory. Our methodology of machine design enables
the sensor to be reconfigurable on the fly, and when scaled up, offers the
potential to make state-of-the art inertial and gravitational sensors that will
have a wide range of potential applications
Life in Hampton Roads Report: The 12th Annual Life in Hampton Roads Survey
[From the Executive Summary]
The Social Science Research Center (SSRC) at Old Dominion University is pleased to present the results from the 12th annual Life in Hampton Roads (LIHR) survey. The purpose of the survey was to gain insight into residents’ perceptions of the quality of life in Hampton Roads. It is important to note that the methodology for this year’s survey differs from previous Life in Hampton Roads surveys. The first ten years of the survey were conducted using a random sample of Hampton Roads residents via telephone. Last year state and university COVID-19 restrictions did not allow for staffing of the SSRC call center during the survey period. Therefore, on-line survey panels were used to solicit respondents to complete a web-based survey. This year, a mixed methods approach of telephone calls and web surveys were used to administer the survey. Given the continued and evolving pandemic conditions in Hampton Roads and the rest of the world, many of this year’s questions focused on residents’ experiences with and responses to continuing COVID-19 conditions
The Grizzly, November 13, 1981
Suspicious Visitor Causes Alarm • Whistle Blowing: The Problem of Ethics in Business • Two Students Caught In Breaking and Entering • Pledging Discussion • Student Teachers Putting in Their Hours • Powlette Speaks on Values • USGA Notes • Students Attend Orchestra Concert in Philadelphia • Ursinus Represented at PCCA Choir Festival • Winterfest Brings Culture Shock to UC • Study Abroad Series: Gidget Goes to Rome • UC Attempts \u27World\u27s Largest Sandcastle\u27 • Davis Selected All-American • Dickinson vs Bears in ECAC Championship • Student Plays for Peru in Pan Am Games • Swimmers Enthusiastic About New Season • Fencing Foils F&M • Bears End Disappointing Season With Loss • Grapplers Anxious To Begin • U.C. Harriers MAC Champs... Againhttps://digitalcommons.ursinus.edu/grizzlynews/1067/thumbnail.jp
High-resolution, H band Spectroscopy of Be Stars with SDSS-III/APOGEE: I. New Be Stars, Line Identifications, and Line Profiles
APOGEE has amassed the largest ever collection of multi-epoch,
high-resolution (R~22,500), H-band spectra for B-type emission line (Be) stars.
The 128/238 APOGEE Be stars for which emission had never previously been
reported serve to increase the total number of known Be stars by ~6%. We focus
on identification of the H-band lines and analysis of the emission peak
velocity separations (v_p) and emission peak intensity ratios (V/R) of the
usually double-peaked H I and non-hydrogen emission lines. H I Br11 emission is
found to preferentially form in the circumstellar disks at an average distance
of ~2.2 stellar radii. Increasing v_p toward the weaker Br12--Br20 lines
suggests these lines are formed interior to Br11. By contrast, the observed IR
Fe II emission lines present evidence of having significantly larger formation
radii; distinctive phase lags between IR Fe II and H I Brackett emission lines
further supports that these species arise from different radii in Be disks.
Several emission lines have been identified for the first time including
~16895, a prominent feature in the spectra for almost a fifth of the sample
and, as inferred from relatively large v_p compared to the Br11-Br20, a tracer
of the inner regions of Be disks. Unlike the typical metallic lines observed
for Be stars in the optical, the H-band metallic lines, such as Fe II 16878,
never exhibit any evidence of shell absorption, even when the H I lines are
clearly shell-dominated. The first known example of a quasi-triple-peaked Br11
line profile is reported for HD 253659, one of several stars exhibiting intra-
and/or extra-species V/R and radial velocity variation within individual
spectra. Br11 profiles are presented for all discussed stars, as are full
APOGEE spectra for a portion of the sample.Comment: accepted in A
The Grizzly, November 6, 1981
Changing Role of Women • Spanish Professor Speaks At Literature Conference • Ursinus Grad Anticipates Changes • Whatley Invited to Testing of Nuclear Sub • USGA Notes • Canterbury Tales: Bawdy Production Rates 10 • Fashion Forum • Myrin Hosts Alumna\u27s Art • Study Abroad Series: Continental Culture • Bear Pack Travels to MACs • Bears Fall to Swarthmore 27-10 • Questionable End to Hockey Seasonhttps://digitalcommons.ursinus.edu/grizzlynews/1066/thumbnail.jp
The Grizzly, October 30, 1981
Founders Day 100th Year of Coeducation • Board of Directors Approve Tuition Increase • Stevens Talks on Hazing to Packed House • Comment: What Eileen Stevens Didn\u27t Say • Drexel-Ursinus Offer Evening Courses at Limerick and UC • Old Men\u27s Undergoes Heating Renovations • ZX Business Society Grows • Lee Savary: Contrasting Natural and Man-made • Study Abroad Series: Seize the Day • Law of the Sea, Law of the Nations • Gridders to Enter New League in 1983 • Bears Lose Homecoming Heartbreaker • X-Country: 38 Straight W\u27s • Field Hockey Trips West Chester 3-0https://digitalcommons.ursinus.edu/grizzlynews/1065/thumbnail.jp
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