Highly indistinguishable and strongly entangled photons from symmetric GaAs quantum dots

The development of scalable sources of non-classical light is fundamental to unlocking thetechnological potential of quantum photonics. Semiconductor quantum dots are emerging asnear-optimal sources of indistinguishable single photons. However, their performance assources of entangled-photon pairs are still modest compared to parametric down converters.Photons emitted from conventional Stranski–Krastanov InGaAs quantum dots have shownnon-optimal levels of entanglement and indistinguishability. For quantum networks, bothcriteria must be met simultaneously. Here, we show that this is possible with a system thathas received limited attention so far: GaAs quantum dots. They can emit triggered polar-ization-entangled photons with high purity (g(2)(0) = 0.002±0.002), high indistinguish-ability (0.93±0.07 for 2 ns pulse separation) and high entanglement fidelity(0.94±0.01). Our results show that GaAs might be the material of choice for quantum-dotentanglement sources in future quantum technologie

Development of nuclear emulsions operating in vacuum for the AEgIS experiment

For the first time the AEgIS (Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy) experiment will measure the Earth\u2019s local gravitational acceleration g on antimatter through the evaluation of the vertical displacement of an antihydrogen horizontal beam. This will be a model independent test of the Weak Equivalence Principle at the base of the general relativity. The initial goal of a g measurement with a relative uncertainty of 1% will be achieved with less than 1000 detected antihydrogens, provided that their vertical position could be determined with a precision of a few micrometers. An emulsion based detector is very suitable for this purpose featuring an intrinsic sub-micrometric spatial resolution. Nevertheless, the AEgIS experiment re- quires unprecedented operational conditions for this type of detector, namely vacuum environment and very low temperature. An intense R&D activity is presently going on to optimize the detector for the AEgIS experimental requirements with rather encouraging results

The Commonwealth march [music] /

Cover title.; Also available online http://nla.gov.au/nla.mus-an4862939; N, GE 130421

DECIPHERING THE ROLE OF TRANSCRIPTION FACTORS IN HUMAN ANTI-TUMOR CD8 T CELL DYSFUNCTION

Studies in mice, particularly those using chronic LCMV infections, identified expression patterns of transcription factors that characterize dysfunctional or exhausted murine CD8 T cells1,2. However, published data about the role of some of these transcription factors implicated in T cell exhaustion are not clear. We intend to approach this question from a different perspective. First, we analyze transcription factor expression patterns in ex vivo human CD8 T cells obtained from the blood, ascites and solid tumors of ovarian carcinoma patients by flow cytometry. We correlate observed expression patterns to the loss of functional markers, such as cytokine production or granzyme B expression. We then analyze the impact of selected transcription factors on T cell function in vitro by inducing or downregulating their expression in tumor-specific human CD8 T cell clones using lentiviruses. Finally, these modified T cell clones will be compared to their control counterparts for their ability to control tumor growth in a human xenograft model

Using Short Pulse Lasers to Address Frontiers in High Pressure Physics

Having laser intensities of 10{sup 21} W/cm{sup 2} yield electrical field strengths of 10{sup 12} V/cm which is comparable to the field strength at the K-shell of neon. Instant field ionization becomes part of the laser-matter interaction allowing to transfer most of the photons momenta directly onto the ions by driving an electrostatic shock through the target equivalent to pressures of several 100 Gbar. Utilization of these high-pressure conditions in form of equation of state measurements, however, strongly depends on the contrast of the femtosecond laser pulse. Currently, the Livermore USP and JanUSP lasers reach contrast values up to 10{sup 8}. This is sufficient to explore near-isochorically heated materials at moderate intensities (10{sup 13}-10{sup 15} W/cm{sup 2}) attaining pressures around 100 Mbar