Macroscopic quantum state

A macroscopic quantum state is a state of matter in which macroscopic properties, such as mechanical motion,[1] thermal conductivity, electrical conductivity[2] and viscosity, can be described only by quantum mechanics rather than merely classical mechanics.[3] This occurs primarily at low temperatures where there is little thermal motion present to mask the quantum nature of a substance.

Macroscopic quantum phenomena can emerge from coherent states of superfluids and superconductors.[4] Quantum states of motion have been directly observed in a macroscopic mechanical resonator (see quantum machine).

References

  1. A. D. O’Connell, M. Hofheinz, M. Ansmann, R. C. Bialczak, M. Lenander, E. Lucero, M. Neeley, D. Sank, H. Wang, M. Weides, J. Wenner, J. M. Martinis, and A. N. Cleland. Quantum ground state and single-phonon control of a mechanical resonator. Nature, 464:697–703, April 2010.
  2. M. Ansmann, H. Wang, R. C. Bialczak, M. Hofheinz, E. Lucero, M. Neeley, A. D. O’Connell, D. Sank, M. Weides, J. Wenner, A. N. Cleland, John M. Martinis. Violation of Bell’s inequality in Josephson phase qubits. Nature, 461:504-506 September 2009.
  3. Jaeger, Gregg (September 2014). "What in the (quantum) world is macroscopic?". American Journal of Physics. 82 (9): 896–905. Bibcode:2014AmJPh..82..896J. doi:10.1119/1.4878358.
  4. Jaeger, Gregg (September 2014). "What in the (quantum) world is macroscopic?". American Journal of Physics. 82 (9): 896–905. Bibcode:2014AmJPh..82..896J. doi:10.1119/1.4878358.


This article is issued from Wikipedia - version of the 6/4/2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.