Suchergebnisse

7 pags., 5 figs. ; We propose a quantum simulation of the quantum Rabi model in an atomic quantum dot, which is a single atom in a tight optical trap coupled to the quasiparticle modes of a superfluid Bose-Einstein condensate. This widely tunable setup allows us to simulate the ultrastrong coupling regime of light-matter interaction in a system which enjoys an amenable characteristic time scale, paving the way for an experimental analysis of the transition between the Jaynes-Cummings and the quantum Rabi dynamics using cold-atom systems. Our scheme can be naturally extended to simulate multiqubit quantum Rabi models. In particular, we discuss the appearance of effective two-qubit interactions due to phononic exchange, among other features. ; under the Marie Curie Actions-COFUND of the FP7. G.R. acknowledges the support from the Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT, Chile) under Grant No. 1150653. E.S. acknowledges financial support from the Spanish MINECO/FEDER under Grant No. FIS2015-69983-P and the Basque Government under Grant No. IT986-16. Financial support by the Fundación General CSIC (Programa ComFuturo) is acknowledged by C.S as well as additional support from the Spanish MINECO/FEDER under Grant No. FIS2015-70856-P and the CAM PRICYT Project QUITEMAD+S2013/ICE-2801. ; Peer Reviewed

6 pags., 2 figs. -- ERRATUM: Publisher's Note: Simulating superluminal physics with superconducting circuit technology [Phys. Rev. A 96, 032121 (2017)] Carlos Sabín, Borja Peropadre, Lucas Lamata, and Enrique Solano Phys. Rev. A 96, 049904 (2017) ; We provide tools for the quantum simulation of superluminal motion with superconducting circuits. We show that it is possible to simulate the motion of a superconducting qubit at constant velocities that exceed the speed of light in the electromagnetic medium and the subsequent emission of Ginzburg radiation. We also consider possible setups for simulating the superluminal motion of a mirror, finding a link with the super-radiant phase transition of the Dicke model. ; Financial support from the Fundación General CSIC is acknowledged by C.S. We also acknowledge support from Spanish MINECO/FEDER FIS2015-69983-P and FIS2015- 70856-P, Ramón y Cajal Grant No. RYC-2012-11391, CAM PRICYT Project QUITEMAD+ S2013/ICE-2801, Basque Government IT986-16, and UPV/EHU UFI 11/55. ; Peer Reviewed

10 pags., 9 figs., 3 apps. ; The generation of photons from the vacuum by means of the movement of a mirror is known as the dynamical Casimir effect (DCE). In general, this phenomenon is effectively described by a field with time-dependent boundary conditions. Alternatively, we introduce a microscopic model of the DCE capable of capturing the essential features of the effect with no time-dependent boundary conditions. Besides the field, such a model comprises a subsystem representing the mirror's internal structure. In this work, we study one of the most straightforward mirror systems: a qubit moving in a cavity and coupled to one of the bosonic modes. We find that under certain conditions on the qubit's movement that do not depend on its physical properties, a large number of photons may be generated without changing the qubit state, as should be expected for a microscopic model of the mirror. ; A.A. and C.S. have received financial support through the Postdoctoral Junior Leader Fellowship Programme from la Caixa Banking Foundation (LCF/BQ/LR18/11640005). L.G.-Á. acknowledges support from the Knut and Alice Wallenberg Foundation through the Wallenberg Center for Quantum Technology (WACQT). E.S. acknowledges financial support from Spanish MCIU/AEI/FEDER (PGC2018-095113- B-I00), Basque Government IT986-16, projects QMiCS (820505) and Open- SuperQ (820363) of EU Flagship on Quantum Technologies, EU FET Open Grant Quromorphic, and Shanghai STCSM (Grant No. 2019SHZDZX01-ZX04).

7 pags., 5 figs. -- Open Access funded by Creative Commons Atribution Licence 4.0 ; We show that simulated relativistic motion can generate entanglement between artificial atoms and protect them from spontaneous emission. We consider a pair of superconducting qubits coupled to a resonator mode, where the modulation of the coupling strength can mimic the harmonic motion of the qubits at relativistic speeds, generating acceleration radiation. We find the optimal feasible conditions for generating a stationary entangled state between the qubits when they are initially prepared in their ground state. Furthermore, we analyse the effects of motion on the probability of spontaneous emission in the standard scenarios of single-atom and two-atom superradiance, where one or two excitations are initially present. Finally, we show that relativistic motion induces sub-radiance and can generate a Zeno-like effect, preserving the excitations from radiative decay. ; MINECO/FEDER FIS2015-69983-P and FIS2015-70856-P, Basque Government grant IT986-16, CAM PRICYT Project QUITEMAD + S2013/ICE-2801, University Sorbonne Paris Cité EQDOL contract, and Fundación General CSIC (Programa ComFuturo). ; Peer Reviewed

7 pags., 4 figs. ; The quantum Rabi model describes the interaction between a two-level quantum system and a single bosonic mode. We propose a method to perform a quantum simulation of the quantum Rabi model, introducing an implementation of the two-level system provided by the occupation of Bloch bands in the first Brillouin zone by ultracold atoms in tailored optical lattices. The effective qubit interacts with a quantum harmonic oscillator implemented in an optical dipole trap. Our realistic proposal allows one to experimentally investigate the quantum Rabi model for extreme parameter regimes, which are not achievable with natural light-matter interactions.When the simulated wave function exceeds the validity region of the simulation, we identify a generalized version of the quantum Rabi model in a periodic phase space. ; This work was supported in part by the DFG (Grant No. We 5 1748-20). S.F. acknowledges funding from the PRESTIGE program, under the Marie Curie Actions-COFUND of the FP7 and from University Sorbonne Paris Cite EQDOL contract. E.R. and E.S. acknowledge funding from UPV/EHU Grant No. UFI 11/55, MINECO/FEDER Grant No. FIS2015- 69983- P, and UPV/EHU Grant No. EHUA15/17. C.S. acknowledges funding from Fundación General CSIC (Programa ComFuturo), MINECO Project No. FIS2015-70856-P (cofinanced by FEDER funds), andCAMPRICYT Project No. QUITEMAD+ S2013/ICE-2801. Basque Government Grant No. IT986-16 Spanish MINECO/FEDER FIS2015-69983-P and FIS2015-70856-P. ; Peer Reviewed

We design a quantum simulator for the Majorana equation, a non-Hamiltonian relativistic wave equation that might describe neutrinos and other exotic particles beyond the standard model. Driven by the need of the simulation, we devise a general method for implementing a number of mathematical operations that are unphysical, including charge conjugation, complex conjugation, and time reversal. Furthermore, we describe how to realize the general method in a system of trapped ions. The work opens a new front in quantum simulations. ; The authors acknowledge funding from Basque Government Grants No. BFI08.211, IT559-10, and No. IT472-10; Spanish MICINN FIS2008-05705, FIS2009- 10061, and FIS2009-12773-C02-01; QUITEMAD; the EC Marie-Curie program; and the CCQED and SOLID European projects. ; Peer Reviewed