2,848 research outputs found
The refractive characteristics and intraocular tensions of colony chimpanzees Technical report, Aug. 1965
Refraction and intraocular pressure tests of colony chimpanzees - age relationshi
Ultrasound and phakometry measurements of the primate eye Technical report, Aug. 1965
Ultrasonic testing and phakometry measurements of primate ey
Polarization correlated photons from a positively charged quantum dot
Polarized cross-correlation spectroscopy on a quantum dot charged with a
single hole shows the sequential emission of photons with common circular
polarization. This effect is visible without magnetic field, but becomes more
pronounced as the field along the quantization axis is increased. We interpret
the data in terms of electron dephasing in the X+ state caused by the
Overhauser field of nuclei in the dot. We predict the correlation timescale can
be increased by accelerating the emission rate with cavity-QED
Batrachochytrium salamandrivorans
An Martel, University of Ghent, provided the micrograph of B. salamandrivorans, in which (left) Bsal sporangia in mTGhL media develop discharge tubes (arrow) to release zoospores, and (right) a scanning electron microscopic image of Bsal with rhizoids. Duncan Wilson and Matthew Fisher provided valuable comments.Peer reviewedPostprin
Synima : a Synteny imaging tool for annotated genome assemblies
Acknowledgements I would like to thank Chris Desjardins and Brian Haas for assistance and contributions to the ortholog prediction code and pipeline, and José Muñoz and anonymous reviewer 1 for code testing. Funding This work was supported by an MIT / Wellcome Trust Fellowship. Availability of data and materials Synima is open source and freely available from https://github.com/rhysf/ Synima under the MIT License. The download includes all example data presented in this manuscript.Peer reviewedPublisher PD
Observation of a two-dimensional spin-lattice in non-magnetic semiconductor heterostructures
Tunable magnetic interactions in high-mobility nonmagnetic semiconductor
heterostructures are centrally important to spin-based quantum technologies.
Conventionally, this requires incorporation of "magnetic impurities" within the
two-dimensional (2D) electron layer of the heterostructures, which is achieved
either by doping with ferromagnetic atoms, or by electrostatically printing
artificial atoms or quantum dots. Here we report experimental evidence of a
third, and intrinsic, source of localized spins in high-mobility GaAs/AlGaAs
heterostructures, which are clearly observed in the limit of large setback
distance (=80 nm) in modulation doping. Local nonequilibrium transport
spectroscopy in these systems reveals existence of multiple spins, which are
located in a quasi-regular manner in the 2D Fermi sea, and mutually interact at
temperatures below 100 milliKelvin via the Ruderman-Kittel-Kasuya-Yosida (RKKY)
indirect exchange. The presence of such a spin-array, whose microscopic origin
appears to be disorder-bound, simulates a 2D lattice-Kondo system with
gate-tunable energy scales.Comment: 7 pages + 4 figs. To appear in Nature Physics. This is the original
submitted version. Final version will be posted six months after publication.
The Supplementary Information can be downloaded from:
http://www.physics.iisc.ernet.in/~arindam/Supplementary_Information_NPHYS-2006-08-0
0812B.pd
Free induction decay of a superposition stored in a quantum dot
We study the free evolution of a superposition initialized with high fidelity
in the neutral-exciton state of a quantum dot. Readout of the state at later
times is achieved by polarized photon detection, averaged over a large number
of cycles. By controlling the fine-structure splitting (FSS) of the dot with a
dc electric field, we show a reduction in the degree of polarization of the
signal when the splitting is minimized. In analogy with the "free induction
decay" observed in nuclear magnetic resonance, we attribute this to hyperfine
interactions with nuclei in the semiconductor. We numerically model this effect
and find good agreement with experimental studies. Our findings have
implications for storage of superpositions in solid-state systems and for
entangled photon pair emission protocols that require a small value of the FSS
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