2009年03月05日

Earthquaks : the endgame

Once on Earthquake has been initiated the question arises, where will it end ? Hou big an earthque will it be? Analysis of the mapped surface rupture trances of 22 historical strike-slip earthquaks, the first at San Andreas, California in 1857 and the moust reccent at Denali, Alaska in 2002, Shows that rupture endpoints frequenty coincide with fault steps or the termini of active fault traces, and that a fault step of more than 3 or 4 km effectively stops an earthquake rupture in tracks.

These findings are relevant to seismic hazard analysis by suggesting limits on the probable extent of future earthquaks on known active faults.


### DataBace ###
nature Vol.444 243-400 Issue no.7117 16 November 2007
News and Views p.276 / SEISMOLOGY : Greatness Thrust upon then / James F. Doldan
Letter p.358 / Predicting the endpoints of earthquake rupturs / Steven G. Wesnousky (University of Nevada)

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posted by 0≠素子 at 10:07| Comment(0) | quantum information | このブログの読者になる | 更新情報をチェックする

2009年02月28日

Moving memories

The transfer of information between the entities that do the processing and memory is crucial - and problematic - for quantum computation. In classical systems, information transfer can include a copying step, where errors can be spotted and crrected, but in quantum systems copying is fundamentally precluded.

Morton et al. demonstrate a technology that could solve the problem : the coherent storage and readout of information between electron-spin processing elements and memory elemrnts based on a nuclear spin. The system utilizes phosphourus-31 spin donors in a silicon -28 crystal.

The nuclear spin acts as a memory element that can store the full state of the electron spin for over a second, then transfer it back to the electron spin at about 90% sfficiency.


### DataBace ###
nature Vol.455 1007-1148 Issue no.7216 23 October 2008
Letter p.1085 / Solid-state quantum memory using the ^31~P nuclear spin / J J L Morton et al. (Oxford Univirsity)
* refarence

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