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González-Gutiérrez C, García-Pons D, Zueco D, Martínez-Pérez MJ. Scanning Spin Probe Based on Magnonic Vortex Quantum Cavities. ACS Nano 2024; 18:4717-4725. [PMID: 38271997 PMCID: PMC10867890 DOI: 10.1021/acsnano.3c06704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
Performing nanoscale scanning electron paramagnetic resonance (EPR) requires three essential ingredients: First, a static magnetic field together with field gradients to Zeeman split the electronic energy levels with spatial resolution; second, a radio frequency (rf) magnetic field capable of inducing spin transitions; finally, a sensitive detection method to quantify the energy absorbed by spins. This is usually achieved by combining externally applied magnetic fields with inductive coils or cavities, fluorescent defects, or scanning probes. Here, we theoretically propose the realization of an EPR scanning sensor merging all three characteristics into a single device: the vortex core stabilized in ferromagnetic thin-film discs. On one hand, the vortex ground state generates a significant static magnetic field and field gradients. On the other hand, the precessional motion of the vortex core around its equilibrium position produces a circularly polarized oscillating magnetic field, which is enough to produce spin transitions. Finally, the spin-magnon coupling broadens the vortex gyrotropic frequency, suggesting a direct measure of the presence of unpaired electrons. Moreover, the vortex core can be displaced by simply using external magnetic fields of a few mT, enabling EPR scanning microscopy with large spatial resolution. Our numerical simulations show that, by using low damping magnets, it is theoretically possible to detect single spins located on the disc's surface. Vortex nanocavities could also attain strong coupling to individual spin molecular qubits with potential applications to mediate qubit-qubit interactions or to implement qubit readout protocols.
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Affiliation(s)
- Carlos
A. González-Gutiérrez
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza ES-50009, Spain
- Department
of Physics and Applied Physics, University
of Massachusetts, Lowell, Massachusetts 01854, United States
- Instituto
de Ciencias Físicas, Universidad
Nacional Autónoma de México, Av. Universidad s/n, Cuernavaca, Morelos 62210, México
| | - David García-Pons
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza ES-50009, Spain
| | - David Zueco
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza ES-50009, Spain
| | - María José Martínez-Pérez
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza ES-50009, Spain
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2
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Downing CA, Zueco D. Non-reciprocal population dynamics in a quantum trimer. Proc Math Phys Eng Sci 2021; 477:20210507. [PMID: 35153597 PMCID: PMC8595999 DOI: 10.1098/rspa.2021.0507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/20/2021] [Indexed: 11/22/2022] Open
Abstract
We study a quantum trimer of coupled two-level systems beyond the single-excitation sector, where the coherent coupling constants are ornamented by a complex phase. Accounting for losses and gain in an open quantum systems approach, we show how the mean populations of the states in the system crucially depend on the accumulated phase in the trimer. Namely, for non-trivial accumulated phases, the population dynamics and the steady states display remarkable non-reciprocal behaviour in both the singly and doubly excited manifolds. Furthermore, while the directionality of the resultant chiral current is primarily determined by the accumulated phase in the loop, the sign of the flow may also change depending on the coupling strength and the amount of gain in the system. This directionality paves the way for experimental studies of chiral currents at the nanoscale, where the phases of the complex hopping parameters are modulated by magnetic or synthetic magnetic fields.
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Affiliation(s)
- C. A. Downing
- Department of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, UK
| | - D. Zueco
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain
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3
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Román-Roche J, Luis F, Zueco D. Photon Condensation and Enhanced Magnetism in Cavity QED. Phys Rev Lett 2021; 127:167201. [PMID: 34723605 DOI: 10.1103/physrevlett.127.167201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 08/25/2021] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
A system of magnetic molecules coupled to microwave cavities (LC resonators) undergoes the equilibrium superradiant phase transition. The transition is experimentally observable. The effect of the coupling is first illustrated by the vacuum-induced ferromagnetic order in a quantum Ising model and then by the modification of the magnetic phase diagram of Fe_{8} dipolar crystals, exemplifying the cooperation between intrinsic and photon-induced spin-spin interactions. Finally, a transmission experiment is shown to resolve the transition, measuring the quantum electrodynamical control of magnetism.
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Affiliation(s)
- Juan Román-Roche
- Instituto de Nanociencia y Materiales de Aragón (INMA) and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain
| | - Fernando Luis
- Instituto de Nanociencia y Materiales de Aragón (INMA) and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain
| | - David Zueco
- Instituto de Nanociencia y Materiales de Aragón (INMA) and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain
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4
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Gimeno I, Urtizberea A, Román-Roche J, Zueco D, Camón A, Alonso PJ, Roubeau O, Luis F. Broad-band spectroscopy of a vanadyl porphyrin: a model electronuclear spin qudit. Chem Sci 2021; 12:5621-5630. [PMID: 34168797 PMCID: PMC8179683 DOI: 10.1039/d1sc00564b] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/09/2021] [Indexed: 01/08/2023] Open
Abstract
We explore how to encode more than a qubit in vanadyl porphyrin molecules hosting a S = 1/2 electronic spin coupled to a I = 7/2 nuclear spin. The spin Hamiltonian and its parameters, as well as the spin dynamics, have been determined via a combination of electron paramagnetic resonance, heat capacity, magnetization and on-chip magnetic spectroscopy experiments performed on single crystals. We find low temperature spin coherence times of micro-seconds and spin relaxation times longer than a second. For sufficiently strong magnetic fields (B > 0.1 T, corresponding to resonance frequencies of 9-10 GHz) these properties make vanadyl porphyrin molecules suitable qubit realizations. The presence of multiple equispaced nuclear spin levels then merely provides 8 alternatives to define the '1' and '0' basis states. For lower magnetic fields (B < 0.1 T), and lower frequencies (<2 GHz), we find spectroscopic signatures of a sizeable electronuclear entanglement. This effect generates a larger set of allowed transitions between different electronuclear spin states and removes their degeneracies. Under these conditions, we show that each molecule fulfills the conditions to act as a universal 4-qubit processor or, equivalently, as a d = 16 qudit. These findings widen the catalogue of chemically designed systems able to implement non-trivial quantum functionalities, such as quantum simulations and, especially, quantum error correction at the molecular level.
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Affiliation(s)
- Ignacio Gimeno
- Instituto de Nanociencia y Materiales de Aragón, CSIC and Universidad de Zaragoza 50009 Zaragoza Spain
| | - Ainhoa Urtizberea
- Instituto de Nanociencia y Materiales de Aragón, CSIC and Universidad de Zaragoza 50009 Zaragoza Spain
- Centro Universitario de la Defensa 50090 Zaragoza Spain
| | - Juan Román-Roche
- Instituto de Nanociencia y Materiales de Aragón, CSIC and Universidad de Zaragoza 50009 Zaragoza Spain
| | - David Zueco
- Instituto de Nanociencia y Materiales de Aragón, CSIC and Universidad de Zaragoza 50009 Zaragoza Spain
| | - Agustín Camón
- Instituto de Nanociencia y Materiales de Aragón, CSIC and Universidad de Zaragoza 50009 Zaragoza Spain
| | - Pablo J Alonso
- Instituto de Nanociencia y Materiales de Aragón, CSIC and Universidad de Zaragoza 50009 Zaragoza Spain
| | - Olivier Roubeau
- Instituto de Nanociencia y Materiales de Aragón, CSIC and Universidad de Zaragoza 50009 Zaragoza Spain
| | - Fernando Luis
- Instituto de Nanociencia y Materiales de Aragón, CSIC and Universidad de Zaragoza 50009 Zaragoza Spain
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5
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Rubín-Osanz M, Lambert F, Shao F, Rivière E, Guillot R, Suaud N, Guihéry N, Zueco D, Barra AL, Mallah T, Luis F. Chemical tuning of spin clock transitions in molecular monomers based on nuclear spin-free Ni(ii). Chem Sci 2021; 12:5123-5133. [PMID: 34168771 PMCID: PMC8179637 DOI: 10.1039/d0sc05856d] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 02/20/2021] [Indexed: 02/02/2023] Open
Abstract
We report the existence of a sizeable quantum tunnelling splitting between the two lowest electronic spin levels of mononuclear Ni complexes. The level anti-crossing, or magnetic "clock transition", associated with this gap has been directly monitored by heat capacity experiments. The comparison of these results with those obtained for a Co derivative, for which tunnelling is forbidden by symmetry, shows that the clock transition leads to an effective suppression of intermolecular spin-spin interactions. In addition, we show that the quantum tunnelling splitting admits a chemical tuning via the modification of the ligand shell that determines the crystal field and the magnetic anisotropy. These properties are crucial to realize model spin qubits that combine the necessary resilience against decoherence, a proper interfacing with other qubits and with the control circuitry and the ability to initialize them by cooling.
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Affiliation(s)
- Marcos Rubín-Osanz
- Instituto de Nanociencia y Materiales de Aragón, CSIC-Universidad de Zaragoza 50009 Zaragoza Spain
| | - François Lambert
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS, Université Paris-Saclay 91405 Orsay Cedex France
| | - Feng Shao
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS, Université Paris-Saclay 91405 Orsay Cedex France
| | - Eric Rivière
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS, Université Paris-Saclay 91405 Orsay Cedex France
| | - Régis Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS, Université Paris-Saclay 91405 Orsay Cedex France
| | - Nicolas Suaud
- Laboratoire de Chimie et Physique Quantiques, Université Paul Sabatier 31062 Toulouse Cedex 4 France
| | - Nathalie Guihéry
- Laboratoire de Chimie et Physique Quantiques, Université Paul Sabatier 31062 Toulouse Cedex 4 France
| | - David Zueco
- Instituto de Nanociencia y Materiales de Aragón, CSIC-Universidad de Zaragoza 50009 Zaragoza Spain
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques Intenses, CNRS-Univ. Grenoble-Alpes 38042 Grenoble Cedex 9 France
| | - Talal Mallah
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS, Université Paris-Saclay 91405 Orsay Cedex France
| | - Fernando Luis
- Instituto de Nanociencia y Materiales de Aragón, CSIC-Universidad de Zaragoza 50009 Zaragoza Spain
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6
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Gimeno I, Kersten W, Pallarés MC, Hermosilla P, Martínez-Pérez MJ, Jenkins MD, Angerer A, Sánchez-Azqueta C, Zueco D, Majer J, Lostao A, Luis F. Enhanced Molecular Spin-Photon Coupling at Superconducting Nanoconstrictions. ACS Nano 2020; 14:8707-8715. [PMID: 32441922 DOI: 10.1021/acsnano.0c03167] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We combine top-down and bottom-up nanolithography to optimize the coupling of small molecular spin ensembles to 1.4 GHz on-chip superconducting resonators. Nanoscopic constrictions, fabricated with a focused ion beam at the central transmission line, locally concentrate the microwave magnetic field. Drops of free-radical molecules have been deposited from solution onto the circuits. For the smallest ones, the molecules were delivered at the relevant circuit areas by means of an atomic force microscope. The number of spins Neff effectively coupled to each device was accurately determined combining Scanning Electron and Atomic Force Microscopies. The collective spin-photon coupling constant has been determined for samples with Neff ranging between 2 × 106 and 1012 spins, and for temperatures down to 44 mK. The results show the well-known collective enhancement of the coupling proportional to the square root of Neff. The average coupling of individual spins is enhanced by more than 4 orders of magnitude (from 4 mHz up to above 180 Hz), when the transmission line width is reduced from 400 μm down to 42 nm, and reaches maximum values near 1 kHz for molecules located on the smallest nanoconstrictions.
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Affiliation(s)
- Ignacio Gimeno
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Wenzel Kersten
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - María C Pallarés
- Laboratorio de Microscopı́as Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
| | - Pablo Hermosilla
- Laboratorio de Microscopı́as Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
| | - María José Martínez-Pérez
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
- Fundación ARAID, Av. de Ranillas 1-D, 50018 Zaragoza, Spain
| | - Mark D Jenkins
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
| | - Andreas Angerer
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | | | - David Zueco
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
- Fundación ARAID, Av. de Ranillas 1-D, 50018 Zaragoza, Spain
| | - Johannes Majer
- Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Shanghai 201315, China
- National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - Anabel Lostao
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
- Laboratorio de Microscopı́as Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
- Fundación ARAID, Av. de Ranillas 1-D, 50018 Zaragoza, Spain
| | - Fernando Luis
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
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7
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Sánchez-Burillo E, Martín-Moreno L, García-Ripoll JJ, Zueco D. Single Photons by Quenching the Vacuum. Phys Rev Lett 2019; 123:013601. [PMID: 31386390 DOI: 10.1103/physrevlett.123.013601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Indexed: 06/10/2023]
Abstract
Heisenberg's uncertainty principle implies that the quantum vacuum is not empty but fluctuates. These fluctuations can be converted into radiation through nonadiabatic changes in the Hamiltonian. Here, we discuss how to control this vacuum radiation, engineering a single-photon emitter out of a two-level system (2LS) ultrastrongly coupled to a finite-band waveguide in a vacuum state. More precisely, we show the 2LS nonlinearity shapes the vacuum radiation into a non-Gaussian superposition of even and odd cat states. When the 2LS bare frequency lays within the band gaps, this emission can be well approximated by individual photons. This picture is confirmed by a characterization of the ground and bound states, and a study of the dynamics with matrix-product states and polaron Hamiltonian methods.
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Affiliation(s)
| | - L Martín-Moreno
- Instituto de Ciencia de Materiales de Aragón and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, E-50009 Zaragoza, Spain
| | - J J García-Ripoll
- Instituto de Física Fundamental, IFF-CSIC, Calle Serrano 113b, Madrid E-28006
| | - D Zueco
- Instituto de Ciencia de Materiales de Aragón and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, E-50009 Zaragoza, Spain
- Fundación ARAID, Paseo María Agustín 36, E-50004 Zaragoza, Spain
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8
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Abstract
Contrary to the conventional wisdom that deviations from standard thermodynamics originate from the strong coupling to the bath, it is shown that in quantum mechanics, these deviations originate from the uncertainty principle and are supported by the non-Markovian character of the dynamics. Specifically, it is shown that the lower bound of the dispersion of the total energy of the system, imposed by the uncertainty principle, is dominated by the bath power spectrum; therefore, quantum mechanics inhibits the system thermal-equilibrium-state from being described by the canonical Boltzmann's distribution. We show for a wide class of systems, systems interacting via central forces with pairwise-self-interacting environments; this general observation is in sharp contrast to the classical case, for which the thermal equilibrium distribution, irrespective of the interaction strength, is exactly characterized by the canonical Boltzmann distribution; therefore, no dependence on the bath power spectrum is present. We define an effective coupling to the environment that depends on all energy scales in the system and reservoir interaction. Sample computations in regimes predicted by this effective coupling are demonstrated. For example, for the case of strong effective coupling, deviations from standard thermodynamics are present and for the case of weak effective coupling, quantum features such as stationary entanglement are possible at high temperatures.
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Affiliation(s)
- Leonardo A Pachón
- Grupo de Física Teórica y Matemática Aplicada, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia, Calle 70 No. 52-21, Medellín, Colombia
| | - Johan F Triana
- Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA; Calle 70 No. 52-21, Medellín, Colombia
| | - David Zueco
- Instituto de Ciencia de Materiales de Aragón y Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza E-50012, Spain
| | - Paul Brumer
- Chemical Physics Theory Group, Department of Chemistry and Center for Quantum Information and Quantum Control, University of Toronto, Toronto, Ontario M5S 3H6, Canada
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9
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Jenkins MD, Zueco D, Roubeau O, Aromí G, Majer J, Luis F. A scalable architecture for quantum computation with molecular nanomagnets. Dalton Trans 2016; 45:16682-16693. [PMID: 27711709 DOI: 10.1039/c6dt02664h] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A proposal for a magnetic quantum processor that consists of individual molecular spins coupled to superconducting coplanar resonators and transmission lines is carefully examined. We derive a simple magnetic quantum electrodynamics Hamiltonian to describe the underlying physics. It is shown that these hybrid devices can perform arbitrary operations on each spin qubit and induce tunable interactions between any pair of them. The combination of these two operations ensures that the processor can perform universal quantum computations. The feasibility of this proposal is critically discussed using the results of realistic calculations, based on parameters of existing devices and molecular qubits. These results show that the proposal is feasible, provided that molecules with sufficiently long coherence times can be developed and accurately integrated into specific areas of the device. This architecture has an enormous potential for scaling up quantum computation thanks to the microscopic nature of the individual constituents, the molecules, and the possibility of using their internal spin degrees of freedom.
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Affiliation(s)
- M D Jenkins
- Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC and Universidad de Zaragoza, Zaragoza, Spain.
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10
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Sánchez-Burillo E, García-Ripoll J, Martín-Moreno L, Zueco D. Nonlinear quantum optics in the (ultra)strong light-matter coupling. Faraday Discuss 2015; 178:335-56. [PMID: 25760380 DOI: 10.1039/c4fd00206g] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The propagation of N photons in one dimensional waveguides coupled to M qubits is discussed, both in the strong and ultrastrong qubit-waveguide coupling. Special emphasis is placed on the characterisation of the nonlinear response and its linear limit for the scattered photons as a function of N, M, qubit inter distance and light-matter coupling. The quantum evolution is numerically solved via the matrix product states technique. The time evolutions for both the field and qubits are computed. The nonlinear character (as a function of N/M) depends on the computed observable. While perfect reflection is obtained for N/M≅1, photon-photon correlations are still resolved for ratios N/M=non-zero. Inter-qubit distance enhances the nonlinear response. Moving to the ultrastrong coupling regime, we observe that inelastic processes are robust against the number of qubits and that the qubit-qubit interaction mediated by the photons is qualitatively modified. The theory developed in this work models experiments in circuit QED, photonic crystals and dielectric waveguides.
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Affiliation(s)
- Eduardo Sánchez-Burillo
- Instituto de Ciencia de Materiales de Aragón y Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza, E-50009, Spain
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11
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Bochenkov V, Baumberg J, Noginov M, Benz F, Aldewachi H, Schmid S, Podolskiy V, Aizpurua J, Lin K, Ebbesen T, Kornyshev AA, Hutchison J, Matczyszyn K, Kumar S, de Nijs B, Rodríguez Fortuño F, Hugall JT, de Roque P, van Hulst N, Kotni S, Martin O, García de Abajo FJ, Flatté M, Mount A, Moskovits M, Ginzburg P, Zueco D, Zayats A, Oh SH, Chen Y, Richards D, Belardini A, Narang P. Applications of plasmonics: general discussion. Faraday Discuss 2015; 178:435-66. [DOI: 10.1039/c5fd90025e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Sanchez-Burillo E, Zueco D, Garcia-Ripoll JJ, Martin-Moreno L. Scattering in the ultrastrong regime: nonlinear optics with one photon. Phys Rev Lett 2014; 113:263604. [PMID: 25615332 DOI: 10.1103/physrevlett.113.263604] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Indexed: 06/04/2023]
Abstract
The scattering of a flying photon by a two-level system ultrastrongly coupled to a one-dimensional photonic waveguide is studied numerically. The photonic medium is modeled as an array of coupled cavities and the whole system is analyzed beyond the rotating wave approximation using matrix product states. It is found that the scattering is strongly influenced by the single- and multiphoton dressed bound states present in the system. In the ultrastrong coupling regime a new channel for inelastic scattering appears, where an incident photon deposits energy into the qubit, exciting a photon-bound state, and escaping with a lower frequency. This single-photon nonlinear frequency conversion process can reach up to 50% efficiency. Other remarkable features in the scattering induced by counterrotating terms are a blueshift of the reflection resonance and a Fano resonance due to long-lived excited states.
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Affiliation(s)
- E Sanchez-Burillo
- Instituto de Ciencia de Materiales de Aragon and Departamento de Fisica de la Materia Condensada, CSIC-Universidad de Zaragoza, E-50012 Zaragoza, Spain
| | - D Zueco
- Instituto de Ciencia de Materiales de Aragon and Departamento de Fisica de la Materia Condensada, CSIC-Universidad de Zaragoza, E-50012 Zaragoza, Spain and Fundacion ARAID, Paseo Maria Agustin 36, E-50004 Zaragoza, Spain
| | - J J Garcia-Ripoll
- Instituto de Fisica Fundamental, IFF-CSIC, Calle Serrano 113b, E-28006 Madrid, Spain
| | - L Martin-Moreno
- Instituto de Ciencia de Materiales de Aragon and Departamento de Fisica de la Materia Condensada, CSIC-Universidad de Zaragoza, E-50012 Zaragoza, Spain
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13
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Hermoso de Mendoza I, Pachón LA, Gómez-Gardeñes J, Zueco D. Synchronization in a semiclassical Kuramoto model. Phys Rev E Stat Nonlin Soft Matter Phys 2014; 90:052904. [PMID: 25493855 DOI: 10.1103/physreve.90.052904] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Indexed: 06/04/2023]
Abstract
Synchronization is a ubiquitous phenomenon occurring in social, biological, and technological systems when the internal rythms of their constituents are adapted to be in unison as a result of their coupling. This natural tendency towards dynamical consensus has spurred a large body of theoretical and experimental research in recent decades. The Kuramoto model constitutes the most studied and paradigmatic framework in which to study synchronization. In particular, it shows how synchronization appears as a phase transition from a dynamically disordered state at some critical value for the coupling strength between the interacting units. The critical properties of the synchronization transition of this model have been widely studied and many variants of its formulations have been considered to address different physical realizations. However, the Kuramoto model has been studied only within the domain of classical dynamics, thus neglecting its applications for the study of quantum synchronization phenomena. Based on a system-bath approach and within the Feynman path-integral formalism, we derive equations for the Kuramoto model by taking into account the first quantum fluctuations. We also analyze its critical properties, the main result being the derivation of the value for the synchronization onset. This critical coupling increases its value as quantumness increases, as a consequence of the possibility of tunneling that quantum fluctuations provide.
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Affiliation(s)
| | - Leonardo A Pachón
- Grupo de Física Atómica y Molecular, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA; Calle 70 No. 52-21, Medellín, Colombia
| | - Jesús Gómez-Gardeñes
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza, Spain and Instituto de Biocomputación y Física de Sistemas Complejos, Universidad de Zaragoza, E-50018 Zaragoza, Spain
| | - David Zueco
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza, Spain and Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, E-50012 Zaragoza, Spain and Fundación ARAID, Paseo María Agustín 36, E-50004 Zaragoza, Spain
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14
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Abstract
The semiclassical and quantum dynamics of two ultrastrongly coupled nonlinear resonators cannot be explained using the discrete nonlinear Schrödinger equation or the Bose-Hubbard model, respectively. Instead, a model beyond the rotating wave approximation must be studied. In the semiclassical limit this model is not integrable and becomes chaotic for a finite window of parameters. For the quantum dimer we find corresponding regions of stability and chaos. The more striking consequence for both semiclassical and quantum chaos is that the tunneling time between the sites becomes unpredictable. These results, including the transition to chaos, can be tested in experiments with superconducting microwave resonators.
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Affiliation(s)
- Uta Naether
- Instituto de Ciencia de Materiales de Aragón and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
| | | | - Juan José Mazo
- Instituto de Ciencia de Materiales de Aragón and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - David Zueco
- Instituto de Ciencia de Materiales de Aragón and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain and Fundación ARAID, Paseo María Agustín 36, 50004 Zaragoza, Spain
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15
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Peropadre B, Zueco D, Porras D, García-Ripoll JJ. Nonequilibrium and nonperturbative dynamics of ultrastrong coupling in open lines. Phys Rev Lett 2013; 111:243602. [PMID: 24483659 DOI: 10.1103/physrevlett.111.243602] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Indexed: 06/03/2023]
Abstract
The time and space resolved dynamics of a qubit with an Ohmic coupling to propagating 1D photons is studied, from weak coupling to the ultrastrong coupling regime. A nonperturbative study based on matrix product states shows the following results, (i) The ground state of the combined systems contains excitations of both the qubit and the surrounding bosonic field. (ii) An initially excited qubit equilibrates through spontaneous emission to a state, which under certain conditions is locally close to that ground state, both in the qubit and the field. (iii) The resonances of the combined qubit-photon system match those of the spontaneous emission process and also the predictions of the adiabatic renormalization [A. J. Leggett et al., Rev. Mod. Phys. 59, 1 (1987)]. Finally, nonperturbative ab initio calculations show that this physics can be studied using a flux qubit galvanically coupled to a superconducting transmission line.
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Affiliation(s)
- B Peropadre
- Instituto de Física Fundamental IFF-CSIC, Calle Serrano 113b, Madrid E-28006, Spain
| | - D Zueco
- Instituto de Ciencia de Materiales de Aragón y Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza E-50009, Spain and Fundación ARAID, Paseo María Agustín 36, Zaragoza E-50004, Spain
| | - D Porras
- Facultad de CC. Físicas, Universidad Complutense de Madrid, Madrid E-28040, Spain and Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
| | - J J García-Ripoll
- Instituto de Física Fundamental IFF-CSIC, Calle Serrano 113b, Madrid E-28006, Spain
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16
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Quijandría F, Porras D, García-Ripoll JJ, Zueco D. Circuit QED bright source for chiral entangled light based on dissipation. Phys Rev Lett 2013; 111:073602. [PMID: 23992064 DOI: 10.1103/physrevlett.111.073602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 04/01/2013] [Indexed: 06/02/2023]
Abstract
We present a scalable and tunable framework for the quantum simulation of critical dissipative models based on a circuit QED cavity array interacting with driven superconducting qubits. We will show that the strongly correlated many-body state of the cavities can be mapped into the state of propagating photons in a transmission line. This allows not only for an efficient way of accessing the correlations in the many-body system, but also provides a bright source of chiral entangled light where directionality and entanglement are assisted by collective phenomena and breaking of reflection symmetry.
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Affiliation(s)
- Fernando Quijandría
- Instituto de Ciencia de Materiales de Aragón y Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, Zaragoza E-50012, Spain
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17
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Mazo JJ, Fajardo OY, Zueco D. Thermal activation at moderate-to-high and high damping: Finite barrier effects and force spectroscopy. J Chem Phys 2013; 138:104105. [DOI: 10.1063/1.4793983] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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18
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Alonso JL, Castro A, Clemente-Gallardo J, Echenique P, Mazo JJ, Polo V, Rubio A, Zueco D. Non-adiabatic effects within a single thermally averaged potential energy surface: Thermal expansion and reaction rates of small molecules. J Chem Phys 2012; 137:22A533. [DOI: 10.1063/1.4747699] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Sánchez-Burillo E, Duch J, Gómez-Gardeñes J, Zueco D. Quantum navigation and ranking in complex networks. Sci Rep 2012; 2:605. [PMID: 22930671 PMCID: PMC3428603 DOI: 10.1038/srep00605] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 08/07/2012] [Indexed: 11/09/2022] Open
Abstract
Complex networks are formal frameworks capturing the interdependencies between the elements of large systems and databases. This formalism allows to use network navigation methods to rank the importance that each constituent has on the global organization of the system. A key example is Pagerank navigation which is at the core of the most used search engine of the World Wide Web. Inspired in this classical algorithm, we define a quantum navigation method providing a unique ranking of the elements of a network. We analyze the convergence of quantum navigation to the stationary rank of networks and show that quantumness decreases the number of navigation steps before convergence. In addition, we show that quantum navigation allows to solve degeneracies found in classical ranks. By implementing the quantum algorithm in real networks, we confirm these improvements and show that quantum coherence unveils new hierarchical features about the global organization of complex systems.
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Affiliation(s)
- Eduardo Sánchez-Burillo
- Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC-Universidad de Zaragoza, E-50012 Zaragoza, Spain
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20
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Luis F, Repollés A, Martínez-Pérez MJ, Aguilà D, Roubeau O, Zueco D, Alonso PJ, Evangelisti M, Camón A, Sesé J, Barrios LA, Aromí G. Molecular prototypes for spin-based CNOT and SWAP quantum gates. Phys Rev Lett 2011; 107:117203. [PMID: 22026699 DOI: 10.1103/physrevlett.107.117203] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Indexed: 05/31/2023]
Abstract
We show that a chemically engineered structural asymmetry in [Tb2] molecular clusters renders the two weakly coupled Tb3+ spin qubits magnetically inequivalent. The magnetic energy level spectrum of these molecules meets then all conditions needed to realize a universal CNOT quantum gate. A proposal to realize a SWAP gate within the same molecule is also discussed. Electronic paramagnetic resonance experiments confirm that CNOT and SWAP transitions are not forbidden.
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Affiliation(s)
- F Luis
- Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC-Universidad de Zaragoza, E-50009 Zaragoza, Spain.
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21
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Abstract
Decoherence due to contact with a hot environment typically restricts quantum phenomena to the low temperature limit, k_{B}T/ℏω≪1 (ℏω is the typical energy of the system). Here we report the existence of a nonequilibrium state for two coupled, parametrically driven, dissipative harmonic oscillators which, contrary to generalized intuition, has stationary entanglement at high temperatures. This clarifies the role of temperature and could lighten the burden on quantum experiments requiring delicate precooling setups.
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Affiliation(s)
- Fernando Galve
- IFISC (CSIC-UIB), Instituto de Física Interdisciplinar y Sistemas Complejos, Campus Universitat Illes Balears, Palma de Mallorca, Spain
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22
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23
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Andrade X, Castro A, Zueco D, Alonso JL, Echenique P, Falceto F, Rubio Á. Modified Ehrenfest Formalism for Efficient Large-Scale ab initio Molecular Dynamics. J Chem Theory Comput 2009; 5:728-42. [DOI: 10.1021/ct800518j] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xavier Andrade
- Nano-bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Centro Mixto CSIC-UPV, and DIPC, Edificio Korta, Av. Tolosa 72, E-20018 San Sebastián, Spain, Institut für Theoretisch Physik, Freie Universität Berlin, Arnimallee, 14, Berlin 14195, Deutschland, Institut für Physik, Universität Augsburg, Universitätsstraβe 1, D-86135 Augsburg, Germany, Instituto de Biocomputación y Física de Sistemas Complejos (BIFI
| | - Alberto Castro
- Nano-bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Centro Mixto CSIC-UPV, and DIPC, Edificio Korta, Av. Tolosa 72, E-20018 San Sebastián, Spain, Institut für Theoretisch Physik, Freie Universität Berlin, Arnimallee, 14, Berlin 14195, Deutschland, Institut für Physik, Universität Augsburg, Universitätsstraβe 1, D-86135 Augsburg, Germany, Instituto de Biocomputación y Física de Sistemas Complejos (BIFI
| | - David Zueco
- Nano-bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Centro Mixto CSIC-UPV, and DIPC, Edificio Korta, Av. Tolosa 72, E-20018 San Sebastián, Spain, Institut für Theoretisch Physik, Freie Universität Berlin, Arnimallee, 14, Berlin 14195, Deutschland, Institut für Physik, Universität Augsburg, Universitätsstraβe 1, D-86135 Augsburg, Germany, Instituto de Biocomputación y Física de Sistemas Complejos (BIFI
| | - J. L. Alonso
- Nano-bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Centro Mixto CSIC-UPV, and DIPC, Edificio Korta, Av. Tolosa 72, E-20018 San Sebastián, Spain, Institut für Theoretisch Physik, Freie Universität Berlin, Arnimallee, 14, Berlin 14195, Deutschland, Institut für Physik, Universität Augsburg, Universitätsstraβe 1, D-86135 Augsburg, Germany, Instituto de Biocomputación y Física de Sistemas Complejos (BIFI
| | - Pablo Echenique
- Nano-bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Centro Mixto CSIC-UPV, and DIPC, Edificio Korta, Av. Tolosa 72, E-20018 San Sebastián, Spain, Institut für Theoretisch Physik, Freie Universität Berlin, Arnimallee, 14, Berlin 14195, Deutschland, Institut für Physik, Universität Augsburg, Universitätsstraβe 1, D-86135 Augsburg, Germany, Instituto de Biocomputación y Física de Sistemas Complejos (BIFI
| | - Fernando Falceto
- Nano-bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Centro Mixto CSIC-UPV, and DIPC, Edificio Korta, Av. Tolosa 72, E-20018 San Sebastián, Spain, Institut für Theoretisch Physik, Freie Universität Berlin, Arnimallee, 14, Berlin 14195, Deutschland, Institut für Physik, Universität Augsburg, Universitätsstraβe 1, D-86135 Augsburg, Germany, Instituto de Biocomputación y Física de Sistemas Complejos (BIFI
| | - Ángel Rubio
- Nano-bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, Centro Mixto CSIC-UPV, and DIPC, Edificio Korta, Av. Tolosa 72, E-20018 San Sebastián, Spain, Institut für Theoretisch Physik, Freie Universität Berlin, Arnimallee, 14, Berlin 14195, Deutschland, Institut für Physik, Universität Augsburg, Universitätsstraβe 1, D-86135 Augsburg, Germany, Instituto de Biocomputación y Física de Sistemas Complejos (BIFI
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24
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Reuther GM, Zueco D, Hänggi P, Kohler S. Time-resolved measurement of a charge qubit. Phys Rev Lett 2009; 102:033602. [PMID: 19257353 DOI: 10.1103/physrevlett.102.033602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2008] [Indexed: 05/27/2023]
Abstract
We propose a scheme for monitoring coherent quantum dynamics with good time-resolution and low backaction, which relies on the response of the considered quantum system to high-frequency ac driving. An approximate analytical solution of the corresponding quantum master equation reveals that the phase of an outgoing signal, which can directly be measured in an experiment with lock-in technique, is proportional to the expectation value of a particular system observable. This result is corroborated by the numerical solution of the master equation for a charge qubit realized with a Cooper-pair box, where we focus on monitoring coherent oscillations.
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Affiliation(s)
- Georg M Reuther
- Institut für Physik, Universität Augsburg, Universitätsstrasse 1, D-86135 Augsburg, Germany
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25
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26
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García-Palacios JL, Zueco D. Solving spin quantum master equations with matrix continued-fraction methods: application to superparamagnets. ACTA ACUST UNITED AC 2006. [DOI: 10.1088/0305-4470/39/42/005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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27
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Zueco D, Martínez PJ, Floría LM, Falo F. Mode-locking of mobile discrete breathers. Phys Rev E Stat Nonlin Soft Matter Phys 2005; 71:036613. [PMID: 15903611 DOI: 10.1103/physreve.71.036613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2003] [Indexed: 05/02/2023]
Abstract
We study numerically synchronization phenomena of mobile discrete breathers in dissipative nonlinear lattices periodically forced. When varying the driving intensity, the breather velocity generically locks at rational multiples of the driving frequency. In most cases, the locking plateau coincides with the linear stability domain of the resonant mobile breather and desynchronization occurs by the regular appearance of type-I intermittencies. However, some plateaus also show chaotic mobile breathers with locked velocity in the locking region. The addition of a small subharmonic driving tames the locked chaotic solution and enhances the stability of resonant mobile breathers.
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Affiliation(s)
- D Zueco
- Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Spain
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28
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García-Palacios JL, Zueco D. The Caldeira–Leggett quantum master equation in Wigner phase space: continued-fraction solution and application to Brownian motion in periodic potentials. ACTA ACUST UNITED AC 2004. [DOI: 10.1088/0305-4470/37/45/003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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