More Accurate Than Heisenberg Allows? Ludwig-Maximilians-Universitat Munchen (07/27/10)
as it appeared in the June August 2, 2010 edition of ACM TechNews.
Quantum cryptography is the safest data encryption method, and takes advantage of the fact that transmitted information can only be quantified with a strictly limited degree of precision. Scientists at ETH Zurich and Ludwig-Maximilians-Universitat (LMU) in Munich have made a discovery in how the use of a quantum memory impacts this uncertainty. "The result not only enhances our understanding of quantum memories, it also provides us with a method for determining the degree of correlation between two quantum particles," says ETH Zurich professor Matthias Christandl. "Moreover, the effect we have observed could yield a means of testing the security of quantum cryptographic systems." Quantum mechanics dictates that the measurement of a parameter can itself disturb a particle's state, and this effect is harnessed by quantum cryptography to encrypt data and thwart eavesdropping. The LMU and ETH Zurich teams have demonstrated that the result of a measurement on a quantum particle can be predicted with greater accuracy if data about the particle is contained in a quantum memory, which can consist of atoms or ions. View Full Article
