Blog: More Accurate Than Heisenberg Allows?

More Accurate Than Heisenberg Allows?
Ludwig-Maximilians-Universitat Munchen (07/27/10)

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.

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