Pump-Induced Exceptional Points in Lasers (Physics Review Letters)

Scientists Predict Paradoxical Laser Effect

New laser-effect, discovered by scientists from the Vienna University of Technology, Princeton, Yale and ETH Zurich: If coupled, lasers can switch each other off, leading to a “laser blackout.”

Princeton’s Hakan Tureci and Li Ge collaborated with researchers at the Institute for Theoretical Physics at Vienna University of Technology.
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Read the abstract.

M. Liertzer1,*, Li Ge2, A. Cerjan3, A. D. Stone3, H. E. Türeci2,4, and S. Rotter1,†
1Institute for Theoretical Physics, Vienna University of Technology, A-1040 Vienna, Austria, EU; 2Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA; 3Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA; 4Institute for Quantum Electronics, ETH-Zürich, CH-8093 Zürich, Switzerland
Received 2 September 2011; revised 20 January 2012; published 24 April 2012

We demonstrate that the above-threshold behavior of a laser can be strongly affected by exceptional points which are induced by pumping the laser nonuniformly. At these singularities, the eigenstates of the non-Hermitian operator which describes the lasing modes coalesce. In their vicinity, the laser may turn off even when the overall pump power deposited in the system is increased. Such signatures of a pump-induced exceptional point can be experimentally probed with coupled ridge or microdisk lasers. © 2012 American Physical Society

A Universal Method to Produce Low–Work Function Electrodes for Organic Electronics (Science)

Read the abstract: A Universal Method to Produce Low–Work Function Electrodes for Organic Electronics. Zhou, Y et al. Science 20 April 2012: 327-332. Work by researchers at Georgia Institute of Technology in collaboration with Princeton University’s Antoine Kahn.

A global post-transcriptional map of the elements that modulate RNA behavior (Nature)

Read the abstract here:
Systematic discovery of structural elements governing stability of mammalian messenger RNAs.
Goodarzi H, Najafabadi HS, Oikonomou P, Greco TM, Fish L, Salavati R, Cristea IM, Tavazoie S. Nature. 2012 Apr 8. doi: 10.1038/nature11013. [Epub ahead of print]

The international trade of “virtual water” in the form of water-intensive crops can lead to enhanced savings in global water (PNAS)

Read the journal abstract here:
Evolution of the global virtual water trade network.
Dalin C, Konar M, Hanasaki N, Rinaldo A, Rodriguez-Iturbe I.
Proc Natl Acad Sci U S A. 2012 Apr 2. [Epub ahead of print]