A PhD studentship in Theoretical Condensed Matter Physics/Semiconductor Optics is available in the School of Physics at Trinity College Dublin, in the area of many-body phenomena in coupled light-matter systems (such as quantum dots and semiconductor microcavities). The project will explore many-particle effects in decoherence, using radiatively coupled quantum dots as a model system.
Submitted by JMiszczak on Sat, 18/07/2009 - 11:15.
Precise control of quantum effects is vital to the realization of entirely new technologies. For example, a computer based on quantum physical principles is expected to outperform today's classical computers. In communication technology, quantum devices are already commercially available which allow secure transmission of data. Controlling the properties of photons down to the quantum level is at the heart of these technologies. In recent years, scientists in the group of Prof.
In this paper, we present new progress on the study of the symmetric extension criterion for separability. First, we show that a perturbation of order O(1/N) is sufficient and, in general, necessary to destroy the entanglement of any state admitting an N Bose symmetric extension. On the other hand, the minimum amount of local noise necessary to induce separability on states arising from N Bose symmetric extensions with Positive Partial Transpose (PPT) decreases at least as fast as O(1/N^2).
Submitted by JMiszczak on Fri, 10/07/2009 - 10:52.
Single atoms have been spotted doing the quantum version of the random walk by physicists in Germany. This sighting of a “quantum walk” could help in the design of quantum search algorithms, or in the understanding of the transition from the quantum, microscopic world to the classical, macroscopic world.