Physics – Condensed Matter – Mesoscale and Nanoscale Physics
Scientific paper
2001-02-08
Physics
Condensed Matter
Mesoscale and Nanoscale Physics
Typos corrected, invited article to appear in special issue of Chemical Physics on "Quantum Physics of Open Systems"
Scientific paper
10.1016/S0301-0104(01)00303-2
We briefly review the oscillator and spin bath models of quantum environments, which can be used to describe the low-energy dynamics of open quantum systems. We then use them to discuss both the mechanisms causing decoherence at low $T$, and the dynamics of this decoherence. This is done first for a central 2-level system coupled to these environments- the results can be applied to the dynamics of quantum nanomagnets and superconducting SQUIDs, where large-scale tunneling of magnetisation and flux take place. Decoherence in these systems is caused principally by coupling to electrons and nuclear spins, the spin bath couplings are particularly dangerous at low $T$. These models are also generalised to discuss quantum measurements in which the measured system, the measuring apparatus, and the environment are treated quantum mechanically. The results can be used to calculate the dynamics of coupled SQUIDs and/or nanomagnets, in which one acts as a measuring apparatus and the other exhibits large-scale quantum superpositions. The same model can be used to describe coupled qubits.
Dube Martin
Stamp Philip C. E.
No associations
LandOfFree
Mechanisms of Decoherence at Low Temperatures does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Mechanisms of Decoherence at Low Temperatures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mechanisms of Decoherence at Low Temperatures will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-89873