dorsal/arxiv
View SchemaStructure of propagators for quantum nondemolition systems
| Authors | Subhashish Banerjee, R. Ghosh |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0611125 |
| URL | https://arxiv.org/abs/quant-ph/0611125 |
Abstract
In the scheme of a quantum nondemolition (QND) measurement, an observable is measured without perturbing its evolution. In the context of studies of decoherence in quantum computing, we examine the `open' quantum system of a two-level atom, or equivalently, a spin-1/2 system, in interaction with quantum reservoirs of either oscillators or spins, under the QND condition of the Hamiltonian of the system commuting with the system-reservoir interaction. The propagators for these QND Hamiltonians are shown to be connected to the squeezing and rotation operators for the two baths, respectively. Squeezing and rotation being both phase space area-preserving canonical transformations, this brings out an interesting analogy between the energy-preserving QND Hamiltonians and the homogeneous linear canonical transformations.
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"abstract": "In the scheme of a quantum nondemolition (QND) measurement, an observable is\nmeasured without perturbing its evolution. In the context of studies of\ndecoherence in quantum computing, we examine the `open\u0027 quantum system of a\ntwo-level atom, or equivalently, a spin-1/2 system, in interaction with quantum\nreservoirs of either oscillators or spins, under the QND condition of the\nHamiltonian of the system commuting with the system-reservoir interaction. The\npropagators for these QND Hamiltonians are shown to be connected to the\nsqueezing and rotation operators for the two baths, respectively. Squeezing and\nrotation being both phase space area-preserving canonical transformations, this\nbrings out an interesting analogy between the energy-preserving QND\nHamiltonians and the homogeneous linear canonical transformations.",
"arxiv_id": "quant-ph/0611125",
"authors": [
"Subhashish Banerjee",
"R. Ghosh"
],
"categories": [
"quant-ph"
],
"title": "Structure of propagators for quantum nondemolition systems",
"url": "https://arxiv.org/abs/quant-ph/0611125"
},
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