Publications (2022)
Certification of a non-projective qudit measurement using multiport beamsplitters
Authors: Martinez, Daniel; Gomez, Esteban S.; Carine, Jaime; Pereira, Luciano; Delgado, Aldo; Walborn, Stephen P.; Tavakoli, Armin; Lima, Gustavo
Journal: NATURE PHYSICS
Publication date: 2022/12/31
DOI: 10.1038/s41567-022-01845-z
Abstract: The most common form of measurement in quantum mechanics projects a wavefunction onto orthogonal states that correspond to definite outcomes. However, generalized quantum measurements that do not fully project quantum states are possible and have an important role in quantum information tasks. Unfortunately, it is difficult to certify that an experiment harvests the advantages made possible by generalized measurements, especially beyond the simplest […]
Optical isolators based on nonreciprocal four-wave mixing
Authors: Muñoz de las Heras, A.; Carusotto, I.
Journal: PHYSICAL REVIEW A
Publication date: 2022/12/29
DOI: 10.1103/PhysRevA.106.063523
Abstract: In this work we propose and theoretically characterize optical isolators consisting of an all-dielectric and nonmagnetic resonator featuring an intensity-dependent refractive index and a strong coherent field propagating in a single direction. Such devices can be straightforwardly realized in state-of-the-art integrated photonics plat-forms. The mechanism underlying optical isolation is based on the breaking of optical reciprocity induced by the asymmetric action of four-wave mixing processes coupling a strong propagating pump field with copropagating […]
Tailored ion beam for precise colour centre creation
Authors: Tobalina, A.; Munuera-Javaloy, C.; Torrontegui, E.; Muga, J. G.; Casanova, J.
Journal: PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
Publication date: 2022/12/26
Abstract: We present an invariant-based quantum control scheme leading to a highly monochromatic ion beam from a Paul trap. Our protocol is implementable by supplying the segmented electrodes in the trap with voltages of the order of volts. This mitigates the impact of fluctuations in previous designs and leads to a low-dispersion beam of ions. Moreover, our proposal does not rely on […]
Helium nanodroplets as an efficient tool to investigate hydrogen attachment to alkali cations
Authors: Kollotzek, Siegfried; Campos-Martinez, Jose; Bartolomei, Massimiliano; Pirani, Fernando; Tiefenthaler, Lukas; Hernandez, Marta, I; Lazaro, Teresa; Zunzunegui-Bru, Eva; Gonzalez-Lezana, Tomas; Breton, Jose; Hernandez-Rojas, Javier; Echt, Olof; Scheier, Paul
Journal: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Publication date: 2022/12/21
DOI: 10.1039/d2cp03841b
Abstract: We report a novel method to reversibly attach and detach hydrogen molecules to positively charged sodium clusters formed inside a helium nanodroplet host matrix. It is based on the controlled production of multiply charged helium droplets which, after picking up sodium atoms and exposure to H-2 vapor, lead to the formation of […]
A statistical investigation of the rate constants for the H+ + HD reaction at temperatures of astrophysical interest
Authors: Gonzalez-Lezana, Tomas; Hily-Blant, Pierre; Faure, Alexandre
Journal: JOURNAL OF CHEMICAL PHYSICS
Publication date: 2022/12/07
DOI: 10.1063/5.0128598
Abstract: The H+ + HD(v, j) reaction has been investigated in detail by means of a statistical quantum method. State-to-state cross sections and rate constants for transitions between reactants and rovibrational states HD(v’, j’) of the product arrangement with energies below 0.9 eV collision energy [that is, HD(v = 0, j = 0-11) and HD(v = 1, j = 0-6)] have been calculated. For the other product channel, D+ + H-2(v’, j & PRIME;), […]
Laboratory and Astronomical Discovery of Magnesium Dicarbide, MgC2
Authors: Changala, P. B.; Gupta, H.; Cernicharo, J.; Pardo, J. R.; Agundez, M.; Cabezas, C.; Tercero, B.; Guelin, M.; McCarthy, M. C.
Journal: ASTROPHYSICAL JOURNAL LETTERS
Publication date: 2022/12/01
Abstract: We report the detection of magnesium dicarbide, MgC2, in the laboratory at centimeter wavelengths and assign (MgC2)-Mg-24, (MgC2)-Mg-25, and (MgC2)-Mg-26 to 14 unidentified lines in the radio spectrum of the circumstellar envelope of the evolved carbon star IRC+10216. The structure of MgC2 is found to be T-shaped with a highly ionic bond between the metal atom and the C-2 […]
Detection of molecular transitions with nitrogen-vacancy centers and electron-spin labels
Authors: Munuera-Javaloy, C.; Puebla, R.; D’Anjou, B.; Plenio, M. B.; Casanova, J.
Journal: NPJ QUANTUM INFORMATION
Publication date: 2022/11/30
DOI: 10.1038/s41534-022-00653-w
Abstract: We present a protocol that detects molecular conformational changes with two nitroxide electron-spin labels and a nitrogen-vacancy (NV) center in diamond. More specifically, we demonstrate that the NV can detect energy shifts induced by the coupling between electron-spin labels. The protocol relies on the judicious application of microwave and radiofrequency pulses in a range of parameters that ensures stable nitroxide resonances. Furthermore, we demonstrate that our scheme is optimized […]
Quantum dynamics in a single excitation subspace: deviations from eigenstate thermalization via long time correlations
Authors: Nation, Charlie; Porras, Diego
Journal: JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
Publication date: 2022/11/25
Abstract: In this work we study a scenario where unitary quantum dynamics in a many-body interacting system is restricted to a single excitation subspace. We ask how dynamics within to such a subspace may in general differ from predictions of the eigenstate thermalization hypothesis (ETH). We show that for certain initial states and observables, if thermalization occurs, it will not fulfil other key predictions of the ETH; instead following differing generic behaviours. We show […]
Different routes to the classical limit of backflow
Authors: Mousavi, S., V; Miret-Artes, S.
Journal: JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
Publication date: 2022/11/25
Abstract: Decoherence is a well established process for the emergence of classical mechanics in open quantum systems. However, it can have two different origins or mechanisms depending on the dynamics one is considering, speaking then about intrinsic decoherence for isolated systems and environmental decoherence due to dissipation/fluctuations for open systems. This second mechanism can not be considered for backflow since no thermal fluctuation terms can be added in the formalism in order to […]
Imaging the Photodissociation Dynamics and Fragment Alignment of CH2BrI at 193 nm
Authors: Recio, Pedro; Cachon, Javier; Rubio-Lago, Luis; Chicharro, David, V; Zanchet, Alexandre; Limao-Vieira, Paulo; de Oliveira, Nelson; Samartzis, Peter C.; Marggi Poullain, Sonia; Banares, Luis
Journal: JOURNAL OF PHYSICAL CHEMISTRY A
Publication date: 2022/11/17
DOI: 10.1021/acs.jpca.2c058978404
Abstract: The photodissociation dynamics and photofragment alignment of bromoiodomethane (CH2BrI) have been studied at 193 nm using a double experimental and theoretical approach. In addition, the ultraviolet (UV)-vacuum ultraviolet (VUV) absorption spectrum of gas phase CH2BrI has been measured in the photon energy range of 5-11 eV using the VUV Fourier transform spectrometer (FTS) at […]
Discovery of two new interstellar molecules with QUIJOTE: HCCCHCCC and HCCCCS
Authors: Fuentetaja, R.; Agundez, M.; Cabezas, C.; Tercero, B.; Marcelino, N.; Pardo, J. R.; de Vicente, P.; Cernicharo, J.
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2022/11/04
DOI: 10.1051/0004-6361/202245018
Abstract: We report on the discovery of two new molecules, HCCCHCCC and HCCCCS, towards the starless core TMC-1 in the Taurus region from the QUIJOTE line survey in the 31.1-50.2 GHz frequency range. We identify a total of twenty-nine lines of HCCCHCCC and six rotational transitions of HCCCCS. The rotational quantum numbers range from J(u) = 10 up to 15 and K-a
First Detection of Silicon-bearing Molecules in eta Car
Authors: Bordiu, C.; Rizzo, J. R.; Bufano, F.; Quintana-Lacaci, G.; Buemi, C.; Leto, P.; Cavallaro, F.; Cerrigone, L.; Ingallinera, A.; Loru, S.; Riggi, S.; Trigilio, C.; Umana, G.; Sciacca, E.
Journal: ASTROPHYSICAL JOURNAL LETTERS
Publication date: 2022/11/01
Abstract: We present ALMA band 6 observations of the luminous blue variable eta Car obtained within the ALMAGAL program. We report SiO J = 5 -> 4, SiS J = 12 -> 11, and SiN N = 5 -> 4 emission in the equatorial region of the Homunculus nebula, constituting the first […]
Mass spectra and appearance energies of cationic fragments for electron ionization of 2-butanol
Authors: Amorim, R. A. A.; Diniz, A. C.; Oliveira, C. B.; Oliveira Junior, O. L.; Jones, D. B.; Blanco, F.; Garcia, G.; Brunger, M. J.; Lopes, M. C. A.
Journal: EUROPEAN PHYSICAL JOURNAL D
Publication date: 2022/11/01
DOI: 10.1140/epjd/s10053-022-00537-w
Abstract: In this work, the mass spectrum (MS) and the appearance energies (AEs) of the ionic fragments formed in the collisions of electrons with 2-butanol were studied using a HIDEN-EPIC300 mass spectrometer. The MS was acquired for the electron impact energy of 70 eV, in the mass region of 1-75 amu and […]
Open quantum rotors: Connecting correlations and physical currents
Authors: Puebla, Ricardo; Imparato, Alberto; Belenchia, Alessio; Paternostro, Mauro
Journal: PHYSICAL REVIEW RESEARCH
Publication date: 2022/10/28
DOI: 10.1103/PhysRevResearch.4.043066
Abstract: We consider a finite one-dimensional chain of quantum rotors interacting with a set of thermal baths at different temperatures. When the interaction between the rotors is made chiral, such a system behaves as an autonomous thermal motor, converting heat currents into nonvanishing rotational ones. Such a dynamical response is strongly pronounced in the range of the Hamiltonian parameters for which the ground state of the system in the thermodynamic limit exhibits a […]
Gas-phase spectroscopic identification of the chlorovinyl radical
Authors: Cabezas, Carlos; Chang, Ching-Hua; Guillemin, Jean-Claude; Endo, Yasuki
Journal: PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Publication date: 2022/10/27
DOI: 10.1039/d2cp03578b
Abstract: Fourier transform microwave spectra for two isomers of the chlorine substituted vinyl radical have been observed in the 4-52 GHz frequency region. The observed radicals ((2)A ‘) have been generated using electric discharges of diluted dichloro derivatives of ethylene as molecular precursors. Fine and hyperfine components observed for each rotational transition are fully assigned in the present study to two isotopologues (Cl-35 and Cl-37), and precise molecular constants are determined for […]