328,448 research outputs found
Microwave-induced resistance oscillations in a back-gated GaAs quantum well
We performed effective mass measurements employing microwave-induced
resistance oscillation in a tunable-density GaAs/AlGaAs quantum well. Our main
result is a clear observation of an effective mass increase with decreasing
density, in general agreement with earlier studies which investigated the
density dependence of the effective mass employing Shubnikov- de Haas
oscillations. This finding provides further evidence that microwave-induced
resistance oscillations are sensitive to electron-electron interactions and
offer a convenient and accurate way to obtain the effective mass.Comment: 4 pages, 4 figure
Investigating the dynamics of, and interactions between, Shanghai office submarkets
The Shanghai office market has developed rapidly over the past two decades. As a consequence of this development, two, apparently distinct, office submarkets, Puxi and Pudong have developed in central Shanghai. This raises the issue as to whether the Shanghai office market can be viewed as a homogeneous entity or whether there is imperfect substitutability across office locations within the city. The latter case raises the possibility of the existence of office submarkets. In this paper, we examine intra-metropolitan rental dynamics in the Puxi and Pudong submarkets, identifying any interrelationships between these markets, and consider whether they form distinct office submarkets. We find no interaction between the two submarkets. Further, we find no evidence of lead-lag relationships between the two submarkets. Finally, when we test for convergence in rental performance between the two submarkets, the tests reveal that we can reject the null of no convergence
An econometric analysis of Shanghai office rents
The modern commercial office market in Shanghai emerged with Chinaās economic reform and open door policy in the 1980s and grew rapidly at the beginning of 1990s,with increasing demand for office space from foreign and domestic occupiers. Though total real estate investment is skewed towards residential property, office investment has grown by 23% per annual in terms of value and by 24% per annum in terms of completed floor space from 1995 to 2007. The Shanghai office market is of importance for a number of reasons. First, it is one of the largest office markets in China in terms of square footage and in investment terms. Second, the office market is one of most established ones in China and attracts most attention from policy makers, investors, practitioners and academia. However, so far there is little empirical research on the Shanghai office market. This paper will use econometric modelling techniques to investigate office rent determination of the CBD in the central Puxi area, Shanghai, over the period 1991 ā2007. Using a reduced form modelling specification in an error correction framework based on demand and supply interactions, GDP and office stock are found to significantly affect office rental performance in the Shanghai market in the long run. The model also shows that the office market adjusts to equilibrium. This model is then extended to test the impact of foreign direct investment, real interest rates, and vacancy rates on rental determination
Efficient Scheme for Perfect Collective Einstein-Podolsky-Rosen Steering
A practical scheme for the demonstration of perfect one-sided
device-independent quantum secret sharing is proposed. The scheme involves a
three-mode optomechanical system in which a pair of independent cavity modes is
driven by short laser pulses and interact with a movable mirror. We demonstrate
that by tuning the laser frequency to the blue (anti-Stokes) sideband of the
average frequency of the cavity modes, the modes become mutually coherent and
then may collectively steer the mirror mode to a perfect
Einstein-Podolsky-Rosen state. The scheme is shown to be experimentally
feasible, it is robust against the frequency difference between the modes,
mechanical thermal noise and damping, and coupling strengths of the cavity
modes to the mirror.Comment: 9 pages, 4 figure
Constraints on gravity: An evidence against the covariant resolution of the Pioneer anomaly
We consider corrections in the form of to the
Einstein-Hilbert Lagrangian. Then we compute the corrections to the
Schwarszchild geometry due to the inclusion of this general term to the
Lagrangian. We show that
gives rise to a constant anomalous acceleration for objects orbiting the Sun
onward the Sun. This leads to the conclusion that would have covariantly
resolved the Pioneer anomaly if this value of had not
contradicted other observations.
We notice that the experimental bounds on grows stronger in case
we examine the deformation of the space-time geometry around objects lighter
than the Sun. We therefore use the high precision measurements around the Earth
(LAGEOS and LLR) and obtain a very strong constraint on the corrections in the
form of and in particular . This bound requires
.
Therefore it refutes the covariant resolution of the Pioneer anomaly.Comment: ...v5: references added, new discussions adde
- ā¦