Sub–shot-noise sensitivities without entanglement

Benatti, Fabio; Braun, Daniel

doi:10.1103/physreva.87.012340

Cited by 39 publications

(57 citation statements)

References 66 publications

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“…Then, entangled initial states of distinguishable particles are needed in order to obtain sub-shot-noise accuracies. A corresponding statement was proven in (Benatti and Braun, 2013) , where A (respectively B) are hermitian functions of a, a † (respectively b, b † ), strictly vanishes. Hence, in order to be able to estimate θ at all (and even more so to beat the standard quantum limit in terms of the total number of bosons), the separability of the input state or the locality of the unitary operator that imprints θ on the state need to be broken.…”

Section: B Mode Entanglement and Metrology: Bosonsmentioning

confidence: 81%

Quantum-enhanced measurements without entanglement

et al. 2018

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Quantum-enhanced measurements exploit quantum mechanical effects for increasing the sensitivity of measurements of certain physical parameters and have great potential for both fundamental science and concrete applications. Most of the research has so far focused on using highly entangled states, which are, however, difficult to produce and to stabilize for a large number of constituents. In the following we review alternative mechanisms, notably the use of more general quantum correlations such as quantum discord, identical particles, or non-trivial Hamiltonians; the estimation of thermodynamical parameters or parameters characterizing non-equilibrium states; and the use of quantum phase transitions. We describe both theoretically achievable enhancements and enhanced sensitivities, not primarily based on entanglement, that have already been demonstrated experimentally, and indicate some possible future research directions. arXiv:1701.05152v2 [quant-ph]

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Section: B Mode Entanglement and Metrology: Bosonsmentioning

confidence: 81%

Quantum-enhanced measurements without entanglement

et al. 2018

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“…Indeed it has become clear that the smallest amount of Markovian decoherence leads back to the SQL [31][32][33][34], limiting the method to short time analyses [35] or niche applications [36][37][38]. On the other hand, while an entangled state of distinguishable particles is needed for beating the SQL in interferometric metrology, a HL-like scaling can be reached by feeding interferometers with unentangled states of identical particles that cannot be distinguished by any degree of freedom [24][25][26][27][28]. Another strategy is the use of interactions between the N particles [39][40][41].…”

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confidence: 99%

Precision measurements of temperature and chemical potential of quantum gases

Marzolino¹,

Braun²

2013

Phys. Rev. A

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We investigate the sensitivity with which the temperature and the chemical potential characterizing quantum gases can be measured. We calculate the corresponding quantum Fisher information matrices for both fermionic and bosonic gases. For the latter, particular attention is devoted to the situation close to the Bose-Einstein condensation transition, which we examine not only for the standard scenario in three dimensions, but also for generalized condensation in lower dimensions, where the bosons condense in a subspace of Hilbert space instead of a unique ground state, as well as condensation at fixed volume or fixed pressure. We show that Bose Einstein condensation can lead to sub-shot noise sensitivity for the measurement of the chemical potential. We also examine the influence of interactions on the sensitivity in three different models, and show that mean-field and contact interactions deteriorate the sensitivity but only slightly for experimentally accessible weak interactions.

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“…the ability to perform precise measurements, is central for technological and experimental developments. Among the most advanced metrological schemes, there are thermometry [1][2][3][4][5][6][7][8][9][10], magnetometry [11][12][13][14][15][16][17][18], and interferometry [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37]. Recently, also estimations of hamiltonian parameters have been suggested [38][39][40][41].…”

Section: Introductionmentioning

confidence: 99%

Quantum metrology with nonequilibrium steady states of quantum spin chains

Marzolino

Prosen

2014

Phys. Rev. A

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We consider parameter estimations with probes being the boundary driven/dissipated nonequilibrium steady states of XXZ spin 1/2 chains. The parameters to be estimated are the dissipation coupling and the anisotropy of the spin-spin interaction. In the weak coupling regime we compute the scaling of the Fisher information, i.e. the inverse best sensitivity among all estimators, with the number of spins. We find superlinear scalings and transitions between the distinct, isotropic and anisotropic, phases. We also look at the best relative error which decreases with the number of particles faster than the shot-noise only for the estimation of anisotropy.

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Sub–shot-noise sensitivities without entanglement

Cited by 39 publications

References 66 publications

Quantum-enhanced measurements without entanglement

Quantum-enhanced measurements without entanglement

Precision measurements of temperature and chemical potential of quantum gases

Quantum metrology with nonequilibrium steady states of quantum spin chains

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