Quantum-limited metrology with product states
| dc.creator | Boixo, Sergio | |
| dc.creator | Datta, Animesh | |
| dc.creator | Flammia, Steven T. | |
| dc.creator | Shaji, Anil | |
| dc.creator | Bagan, Emilio | |
| dc.creator | Caves, Carlton M. | |
| dc.date | 2007-10-01 | |
| dc.date | 2007-10-20 | |
| dc.date.accessioned | 2026-07-07T08:54:28Z | |
| dc.date.available | 2026-07-07T08:54:28Z | |
| dc.description | We study the performance of initial product states of n-body systems in generalized quantum metrology protocols that involve estimating an unknown coupling constant in a nonlinear k-body (k << n) Hamiltonian. We obtain the theoretical lower bound on the uncertainty in the estimate of the parameter. For arbitrary initial states, the lower bound scales as 1/n^k, and for initial product states, it scales as 1/n^(k-1/2). We show that the latter scaling can be achieved using simple, separable measurements. We analyze in detail the case of a quadratic Hamiltonian (k = 2), implementable with Bose-Einstein condensates. We formulate a simple model, based on the evolution of angular-momentum coherent states, which explains the O(n^(-3/2)) scaling for k = 2; the model shows that the entanglement generated by the quadratic Hamiltonian does not play a role in the enhanced sensitivity scaling. We show that phase decoherence does not affect the O(n^(-3/2)) sensitivity scaling for initial product states. | |
| dc.description | 15 pages, 6 figures | |
| dc.identifier | https://arxiv.org/abs/0710.0285 | |
| dc.identifier | http://arxiv.org/abs/0710.0285 | |
| dc.identifier | Phys. Rev. A 77, 012317 (2007) | |
| dc.identifier | doi:10.1103/PhysRevA.77.012317 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/145943 | |
| dc.subject | Quantum Physics | |
| dc.subject | Other Condensed Matter | |
| dc.title | Quantum-limited metrology with product states | |
| dc.type | text |