16,324 research outputs found
Storage and Retrieval of Thermal Light in Warm Atomic Vapor
We report slowed propagation and storage and retrieval of thermal light in
warm rubidium vapor using the effect of electromagnetically-induced
transparency (EIT). We first demonstrate slowed-propagation of the probe
thermal light beam through an EIT medium by measuring the second-order
correlation function of the light field using the Hanbury-BrownTwiss
interferometer. We also report an experimental study on the effect of the EIT
slow-light medium on the temporal coherence of thermal light. Finally, we
demonstrate the storage and retrieval of thermal light beam in the EIT medium.
The direct measurement of the photon number statistics of the retrieved light
field shows that the photon number statistics is preserved during the storage
and retrieval process.Comment: 4 pages, 4 figure
Reversing the Weak Quantum Measurement for a Photonic Qubit
We demonstrate the conditional reversal of a weak (partial-collapse) quantum
measurement on a photonic qubit. The weak quantum measurement causes a
nonunitary transformation of a qubit which is subsequently reversed to the
original state after a successful reversing operation. Both the weak
measurement and the reversal operation are implemented linear optically. The
state recovery fidelity, determined by quantum process tomography, is shown to
be over 94% for partial-collapse strength up to 0.9. We also experimentally
study information gain due to the weak measurement and discuss the role of the
reversing operation as an information erasure
On the Chaos Bound in Rotating Black Holes
We study out-of-time-order correlators (OTOCs) of rotating BTZ black holes
using two different approaches: the elastic eikonal gravity approximation, and
the Chern-Simons formulations of 3-dimensional gravity. Within both methods the
OTOC is given as a sum of two contributions, corresponding to left and right
moving modes. The contributions have different Lyapunov exponents,
, where
is the angular velocity and is the AdS radius. Since , there is an apparent contradiction with
the chaos bound. We discuss how the result can be made consistent with the
chaos bound if one views as the effective
inverse temperatures of the left and right moving modes.Comment: 35 pages, 2 figures. v2: references added, typos corrected, and
clarifications added to the discussion sectio
NMR study on the stability of the magnetic ground state in MnCrO
The canting angles and fluctuation of the magnetic ion spins of spinel oxide
MnCrO were studied by nuclear magnetic resonance (NMR) at low
temperatures, which has a collinear ferrimagnetic order below and a
ferrimagnetic spiral order below . Contrary to previous reports,
only one spin canting angle of Cr ions was observed. The spin canting angles of
Mn and Cr ions in the ferrimagnetic spiral obtained at a liquid-He temperature
were 43\,^{\circ} and 110\,^{\circ}, respectively. The nuclear spin-spin
relaxation was determined by the Suhl-Nakamura interaction at low temperatures
but the relaxation rate increases rapidly as the temperature
approaches . This indicates that the fluctuation of the spiral component
becomes faster as the temperature increases but not fast enough to leave an
averaged hyperfine field to nuclei in the time scale of nuclear spin precession
in the ferrimagnetic phase, which is on the order of s. The spiral
volume fraction measured for various temperatures reveals that the collinear
and the spiral ferrimagnetic phases are mixed below the transition temperature
of the spiral order. The temperature hysteresis in the volume fraction implies
that this transition has first-order characteristics.Comment: 13 pages, 5 figure
POTENTIAL FOR UTILIZING NATIONAL TRUST MOVEMENT TO PRESERVE TOURISM RESOURCES: A CASE STUDY OF THE UNITED STATES, JAPAN, AND SOUTH KOREA
The tourism industry should consider the preservation of natural and cultural resources because these resources are important as attractions or background to attractions in many popular travel destinations. Regarding environmental conservation and preservation, nongovernmental organizations (NGOs) such as national trusts (NTs) or land trusts (LTs) are playing a major role. Therefore, it was assumed that the members of the NT/LT movement and tourism entities may make good partners in natural and cultural resource preservation and sustainable tourism development. Unpublished secondary data review and in-depth interview skills were utilized to investigate detailed collaborative cases involving tourism entities and LTs in the U.S, and tourism entities and NTs in Japan, and South Korea.
The U.S. LTs, Japanese NTs, and Korean NTs mentioned various types of partnership with tourism entities. They explained the cases of partnership with the purpose of fundraising, public relations, direct land and cultural resource conservation, member’s benefits, and mutual advocacy. NT/LT organizations have begun to consider tourism as their partner for promoting natural and cultural resource preservation. Moreover, tourism has begun to recognize the value in promoting natural and cultural resource awareness, as a means of preserving tourism resources. The results from this study emphasize the convergent needs and goals of LTs/NTs and tourism regarding natural resource conservation. In a cooperative arrangement, the partnership between LTs/NTs and tourism entities would diversify revenue sources and increase public awareness.Submitted to the faculty of the University Graduate School
in partial fulfillment of the requirements for the degree
Master of Sciences in the Department of Recreation, Park, and Tourism Studies
School of Public Health
Indiana Universit
Experimental verification of the commutation relation for Pauli spin operators using single-photon quantum interference
We report experimental verification of the commutation relation for Pauli
spin operators using quantum interference of the single-photon polarization
state. By superposing the quantum operations and on a single-photon polarization state, we have experimentally
implemented the commutator, , and the anticommutator,
, and have demonstrated the relative phase factor
of between and operations. The
experimental quantum operation corresponding to the commutator, , showed process fidelity of 0.94 compared to the ideal
operation and is determined to be .Comment: 4pages, 3 figure
Motivos trabajo inicial y la desmotivación en la enseñanza del inglés como lengua ex- tranjera: Los casos de los profesores coreanos
In order to broaden understanding of English as a foreign language (EFL) tea-
cher motivation, this study examines Korean EFL teachers’ initial job motives and demotiva-
ting factors. Four psychological constructs emerged regarding initial career motives: Global
Orientation, Job Security, Altruism, and Ought-to Self. Among the constructs, global orien-
tation proved to be the most popular reason for choosing an EFL teaching career. This study
also showed three constructs for detrimental factors on EFL teacher motivation: Obstacles to
Communicative Language Teaching, Inadequate Administrative Support, and Lack of Social
Recognition. It was shown that obstacles to communicative language teaching contributed
to the greatest demotivation.Para la comprensión de inglés como lengua extranjera (EFL) motivación del
profesorado, este estudio examina motivos de trabajo inicial y factores desmotivadores de
los profesores coreanos. Cuatro constructos psicológicos surgieron con respecto a los moti-
vos de trabajo inicial: orientación global, seguridad en el empleo, altruismo, y Ought-to Self.
Entre las constructos, orientación global resultó para ser la razón más popular para elegir
una carrera de enseñanza de inglés como lengua extranjera. Este estudio también mostró tres
constructos de factores perjudiciales en EFL motivación del profesorado: Los obstáculos de
enseñanza de ingles como lengua extranjera. Este estudio también mostro tres constructores de factores perjudiciales en EFL motivación del profesorado: Los obstáculos de enseñanza comunicativa, la insuficiencia de apoyo administrativo, y la falta de reconocimiento social. Se ha demostrado que los obstáculos en enseñanza comunicativa ha contribuido a
la mayor desmotivación
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