73 nanotimes News in Brief

Theoretical physicist Ali Naji from the IPM in Tehran and the University of Cambridge, UK, and his colleagues have shown how small random patches of disordered, frozen electric charges can make a difference when they are scattered on surfaces that are overall neutral. These charges induce a twisting force that is strong enough to be felt as far as nanometers or even micrometers away. The authors found that the twisting force, created by virtue of the disorder of surface charges, is expected to be much stronger and far-reaching than the remnant forces. The latter are always present, even in the absence of charge disorder, and are due to fluctuations at the atomic and molecular levels.

Naji A., Sarabadani J., Dean D.S., and Podgornik R. (2012), Sample-to-sample torque fluctuations in a system of coaxial randomly charged surfaces, In: European Physical Journal E, Soft Matter and Biological Physics, Volume 35, Number 3, March 2012, Article 24 [7 Pages], DOI: 10.1140/epje/i2012-12024-y

http://dx.doi.org/10.1140/epje/i2012-12024-y

The promise of ultrafast quantum computing has moved a step closer to reality with a technique to create rewritable computer chips using a beam of light. Researchers from The City College of New York (CCNY) and the University of California Berkeley (UCB, US) used light to control the spin of an atom’s nucleus in order to encode information. The researcher have developed a technique to use laser light to pattern the alignment of "spin" within atoms so that the pattern can be rewritten on the fly. Such a technique may one day lead to rewritable spintronic circuits.

Image: The probe head used to send radio-frequency pulses onto the coil used for pulsed spin manipulation of a gallium arsenide (semiconductor) sample. © Yunpu Li

Jonathan P. King, Yunpu Li, Carlos A. Meriles, Jeffrey A. Reimer: Optically rewritable patterns of nuclear magnetization in gallium arsenide, In: Nature Communications, Vol. 3, June 26, 2012, Article number 918, DOI:10.1038/ncomms1918: http://dx.doi.org/10.1038/ncomms1918

http://india.cchem.berkeley.edu/~reimer/