|
Records |
Links |
|
Author |
Fadel, M.; Yadin, B.; Mao, Y.P.; Byrnes, T.; Gessner, M. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
Multiparameter quantum metrology and mode entanglement with spatially split nonclassical spin ensembles |
Type |
Journal Article |
|
Year ![sorted by Year field, descending order (down)](img/sort_desc.gif) |
2023 |
Publication |
New Journal of Physics |
Abbreviated Journal |
New J. Phys. |
|
|
Volume |
25 |
Issue |
7 |
Pages |
073006 - 25pp |
|
|
Keywords |
quantum metrology; Bose-Einstein condensates; spin-squeezing; Fisher information matrix; mode and particle entanglement |
|
|
Abstract |
We identify the multiparameter sensitivity of entangled spin states, such as spin-squeezed and Dicke states that are spatially distributed into several addressable spatial modes. Analytical expressions for the spin-squeezing matrix of families of states that are accessible by current atomic experiments reveal the quantum gain in multiparameter metrology, as well as the optimal strategies to maximize the sensitivity gain for the estimation of any linear combination of parameters. We further study the mode entanglement of these states by deriving a witness for genuine k-partite mode entanglement from the spin-squeezing matrix. Our results highlight the advantage of mode entanglement for distributed sensing, and outline optimal protocols for multiparameter estimation with nonclassical spatially-distributed spin ensembles. We illustrate our findings with the design of a protocol for gradient sensing with a Bose-Einstein condensate in an entangled spin state in two modes. |
|
|
Address |
[Fadel, Matteo] Swiss Fed Inst Technol, Dept Phys, CH-8093 Zurich, Switzerland, Email: fadelm@phys.ethz.ch; |
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
IOP Publishing Ltd |
Place of Publication |
|
Editor |
|
|
|
Language |
English |
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1367-2630 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
WOS:001026518600001 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
5582 |
|
Permanent link to this record |
|
|
|
|
Author |
Delhom, A.; Olmo, G.J.; Singh, P. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
A diffeomorphism invariant family of metric-affine actions for loop cosmologies |
Type |
Journal Article |
|
Year ![sorted by Year field, descending order (down)](img/sort_desc.gif) |
2023 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
|
|
Volume |
06 |
Issue |
6 |
Pages |
059 - 21pp |
|
|
Keywords |
quantum cosmology; modified gravity; cosmic singularity |
|
|
Abstract |
In loop quantum cosmology (LQC) the big bang singularity is generically resolved by a big bounce. This feature holds even when modified quantization prescriptions of the Hamiltonian constraint are used such as in mLQC-I and mLQC-II. While the later describes an effective description qualitatively similar to that of standard LQC, the former describes an asymmetric evolution with an emergent Planckian de-Sitter pre-bounce phase even in the absence of a potential. We consider the potential relation of these canonically quantized non-singular models with effective actions based on a geometric description. We find a 3-parameter family of metric-affine f (R) theories which accurately approximate the effective dynamics of LQC and mLQC-II in all regimes and mLQC-I in the post-bounce phase. Two of the parameters are fixed by enforcing equivalence at the bounce, and the background evolution of the relevant observables can be fitted with only one free parameter. It is seen that the non-perturbative effects of these loop cosmologies are universally encoded by a logarithmic correction that only depends on the bounce curvature of the model. In addition, we find that the best fit value of the free parameter can be very approximately written in terms of fundamental parameters of the underlying quantum description for the three models. The values of the best fits can be written in terms of the bounce density in a simple manner, and the values for each model are related to one another by a proportionality relation involving only the Barbero-Immirzi parameter. |
|
|
Address |
[Delhom, Adria; Singh, Parampreet] Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA, Email: adria.delhom@gmail.com; |
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
IOP Publishing Ltd |
Place of Publication |
|
Editor |
|
|
|
Language |
English |
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1475-7516 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
WOS:001025410500003 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
5583 |
|
Permanent link to this record |
|
|
|
|
Author |
Nzongani, U.; Zylberman, J.; Doncecchi, C.E.; Perez, A.; Debbasch, F.; Arnault, P. |
![goto web page (via DOI) doi](img/doi.gif)
|
|
Title |
Quantum circuits for discrete-time quantum walks with position-dependent coin operator |
Type |
Journal Article |
|
Year ![sorted by Year field, descending order (down)](img/sort_desc.gif) |
2023 |
Publication |
Quantum Information Processing |
Abbreviated Journal |
Quantum Inf. Process. |
|
|
Volume |
22 |
Issue |
7 |
Pages |
270 - 46pp |
|
|
Keywords |
Quantum walks; Quantum circuits; Quantum simulation |
|
|
Abstract |
The aim of this paper is to build quantum circuits that implement discrete-time quantum walks having an arbitrary position-dependent coin operator. The position of the walker is encoded in base 2: with n wires, each corresponding to one qubit, we encode 2(n) position states. The data necessary to define an arbitrary position-dependent coin operator is therefore exponential in n. Hence, the exponentiality will necessarily appear somewhere in our circuits. We first propose a circuit implementing the position-dependent coin operator, that is naive, in the sense that it has exponential depth and implements sequentially all appropriate position-dependent coin operators. We then propose a circuit that “transfers” all the depth into ancillae, yielding a final depth that is linear in n at the cost of an exponential number of ancillae. Themain idea of this linear-depth circuit is to implement in parallel all coin operators at the different positions. Reducing the depth exponentially at the cost of having an exponential number of ancillae is a goal which has already been achieved for the problem of loading classical data on a quantum circuit (Araujo in Sci Rep 11:6329, 2021) (notice that such a circuit can be used to load the initial state of the walker). Here, we achieve this goal for the problem of applying a position-dependent coin operator in a discrete-time quantum walk. Finally, we extend the result of Welch (New J Phys 16:033040, 2014) from position-dependent unitaries which are diagonal in the position basis to position-dependent 2 x 2-block-diagonal unitaries: indeed, we show that for a position dependence of the coin operator (the block-diagonal unitary) which is smooth enough, one can find an efficient quantum-circuit implementation approximating the coin operator up to an error epsilon (in terms of the spectral norm), the depth and size of which scale as O(1/epsilon). A typical application of the efficient implementation would be the quantum simulation of a relativistic spin-1/2 particle on a lattice, coupled to a smooth external gauge field; notice that recently, quantum spatial-search schemes have been developed which use gauge fields as the oracle, to mark the vertex to be found (Zylberman in Entropy 23:1441, 2021), (Fredon arXiv:2210.13920). A typical application of the linear-depth circuit would be when there is spatial noise on the coin operator (and hence a non-smooth dependence in the position). |
|
|
Address |
[Nzongani, Ugo; Doncecchi, Carlo-Elia; Arnault, Pablo] Univ Paris Saclay, CNRS, INRIA, Lab Methodes Formelles,ENS Paris Saclay, F-91190 Gif Sur Yvette, France, Email: ugo.nzongani@universite-paris-saclay.fr; |
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
Springer |
Place of Publication |
|
Editor |
|
|
|
Language |
English |
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1570-0755 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
WOS:001022408900002 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
5587 |
|
Permanent link to this record |
|
|
|
|
Author |
AGATA Collaboration (Valiente-Dobon, J.J. et al); Perez-Vidal, R.M.; Blasco Miquel, J.; Civera, J.V.; Gadea, A. |
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
Conceptual design of the AGATA 2 pi array at LNL |
Type |
Journal Article |
|
Year ![sorted by Year field, descending order (down)](img/sort_desc.gif) |
2023 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
|
|
Volume |
1049 |
Issue |
|
Pages |
168040 - 14pp |
|
|
Keywords |
AGATA spectrometer; LNL facility; gamma-ray tracking; Pulse shape analysis; PRISMA spectrometer; EUCLIDES detector; DANTE detector; TRACE detector; Plunger device |
|
|
Abstract |
The Advanced GAmma Tracking Array (AGATA) has been installed at Laboratori Nazionali di Legnaro (LNL), Italy. In this installation, AGATA will consist, at the beginning, of 13 AGATA triple clusters (ATCs) with an angular coverage of 1n,and progressively the number of ATCs will increase up to a 2 pi angular coverage. This setup will exploit both stable and radioactive ion beams delivered by the Tandem-PIAVE-ALPI accelerator complex and the SPES facility. The new implementation of AGATA at LNL will be used in two different configurations, firstly one coupled to the PRISMA large-acceptance magnetic spectrometer and lately a second one at Zero Degrees, along the beam line. These two configurations will allow us to cover a broad physics program, using different reaction mechanisms, such as Coulomb excitation, fusion-evaporation, transfer and fission at energies close to the Coulomb barrier. These setups have been designed to be coupled with a large variety of complementary detectors such as charged particle detectors, neutron detectors, heavy-ion detectors, high-energy gamma-ray arrays, cryogenic and gasjet targets and the plunger device for lifetime measurements. We present in this paper the conceptual design, characteristics and performance figures of this implementation of AGATA at LNL. |
|
|
Address |
[Valiente-Dobon, J. J.; Goasduff, A.; Angelini, F.; Balogh, M.; Brugnara, D.; Cocconi, P.; Cogo, A.; Collado, J.; Ertoprak, A.; Galtarossa, F.; Gambalonga, A.; Gongora Servin, B.; Gottardo, A.; Gozzelino, A.; Gulmini, M.; Marchi, T.; Modanese, P.; Napoli, D. R.; Pellumaj, J.; Perez-Vidal, R. M.; Pilotto, E.; Raniero, W.; Rosso, D.; Scarpa, D.; Sedlak, M.; Toniolo, N.; Volpe, V.; Zago, L.; Zanon, I.; Allegrini, M. L.; Benini, D.; Biasotto, M.; Corradi, L.; De Angelis, G.; De Ruvo, L.; Fantinel, S.; Fioretto, E.; Minarello, A.; Stefanini, A. M.] INFN, Lab Nazl Legnaro, Legnaro, Italy, Email: valiente@lnl.infn.it |
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
Elsevier |
Place of Publication |
|
Editor |
|
|
|
Language |
English |
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0168-9002 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
WOS:001020811800001 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
5590 |
|
Permanent link to this record |
|
|
|
|
Author |
n_TOF Collaboration (Patronis, N. et al); Babiano-Suarez, V.; Balibrea Correa, J.; Domingo-Pardo, C.; Ladarescu, I.; Lerendegui-Marco, J. |
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
Status report of the n_TOF facility after the 2nd CERN long shutdown period |
Type |
Journal Article |
|
Year ![sorted by Year field, descending order (down)](img/sort_desc.gif) |
2023 |
Publication |
EPJ Techniques and Instrumentation |
Abbreviated Journal |
EPJ Tech. Instrum. |
|
|
Volume |
10 |
Issue |
1 |
Pages |
13 - 10pp |
|
|
Keywords |
Neutron time of flight; Spallation target; Nuclear astrophysics; Neutron physics; Neutron induced fission; Neutron reactions |
|
|
Abstract |
During the second long shutdown period of the CERN accelerator complex (LS2, 2019-2021), several upgrade activities took place at the nTOF facility. The most important have been the replacement of the spallation target with a next generation nitrogen-cooled lead target. Additionally, a new experimental area, at a very short distance from the target assembly (the NEAR Station) was established. In this paper, the core commissioning actions of the new installations are described. The improvement in the nTOF infrastructure was accompanied by several detector development projects. All these upgrade actions are discussed, focusing mostly on the future perspectives of the n_TOF facility. Furthermore, some indicative current and future measurements are briefly reported. |
|
|
Address |
[Patronis, N.; Goula, S.; Eleme, Z.; Stamati, M. E.; Vagena, E.] Univ Ioannina, Ioannina, Greece, Email: nikolaos.patronis@cern.ch |
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
Springer |
Place of Publication |
|
Editor |
|
|
|
Language |
English |
Summary Language |
|
Original Title |
|
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2195-7045 |
ISBN |
|
Medium |
|
|
|
Area |
|
Expedition |
|
Conference |
|
|
|
Notes |
WOS:001008786600001 |
Approved |
no |
|
|
Is ISI |
yes |
International Collaboration |
yes |
|
|
Call Number |
IFIC @ pastor @ |
Serial |
5591 |
|
Permanent link to this record |