A5062350535- Quantum Information and Cryptography
- Quantum optics and atomic interactions
- Quantum Computing Algorithms and Architecture
- Quantum Mechanics and Applications
- Mechanical and Optical Resonators
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum and electron transport phenomena
- Neural Networks and Reservoir Computing
- Spectroscopy and Quantum Chemical Studies
- Advanced Thermodynamics and Statistical Mechanics
- Laser-Matter Interactions and Applications
- Photonic and Optical Devices
- Atomic and Subatomic Physics Research
- Strong Light-Matter Interactions
- Quantum-Dot Cellular Automata
- Cloud Computing and Resource Management
- Laser Design and Applications
- Random lasers and scattering media
- Quantum many-body systems
- Nonlinear Dynamics and Pattern Formation
- Neutrino Physics Research
- Quantum Electrodynamics and Casimir Effect
- Parallel Computing and Optimization Techniques
- Advanced Fiber Laser Technologies
- stochastic dynamics and bifurcation
Universidade Federal de São Carlos
2016-2025
Max Planck Institute of Quantum Optics
2009-2011
We calculate the dissipative dynamics of two-qubit quantum discord under Markovian environments. analyze various channels such as dephasing, depolarizing, and generalized amplitude damping, assuming independent perturbation, in which each qubit is coupled to its own channel. Choosing initial conditions that manifest so-called sudden death entanglement, we compare entanglement with discord. show all cases where suddenly disappears, vanishes only asymptotic limit, behaving similarly individual...
Quantum batteries are miniature energy storage devices and play a very important role in quantum thermodynamics. In recent years, have been extensively studied, but limited theoretical level. Here we report the experimental realization of battery based on superconducting qubits. Our model explores dark bright states to achieve stable powerful charging processes, respectively. scheme makes use adiabatic brachistochrone, which allows us speed up {battery ergotropy injection. Due inherent...
Abstract We perform an experiment in which a quantum heat engine works under two reservoirs, one at positive spin temperature and the other effective negative i.e., when system presents population inversion. show that efficiency of this can be greater than both reservoirs are temperatures. also demonstrate counter-intuitive result Otto beaten only is operating finite-time mode.
The quantum Rabi model is in the scientific spotlight due to recent theoretical and experimental progress. Nevertheless, a full-fledged classification of its coupling regimes remains as relevant open question. We propose spectral dividing into three regions based on validity perturbative criteria model, which allows us use exactly solvable effective Hamiltonians. These are (i) ultrastrong regime comprises Jaynes-Cummings (ii) region where nonperturbative deep strong coexist, (iii) regime....
Abstract A fast and scalable scheme for multi-qubit resetting in superconducting quantum processors is proposed by exploiting the feasibility of frequency-tunable transmon qubits transmon-like couplers to engineer a full programmable erasing head. We demonstrate emergence collective effects that lead decoherence-free subspace during process. The presence such negatively impacts device's performance has been overlooked other chips. To circumvent this issue pave way scalability, we employ...
We study numerically the dynamics of Rabi Hamiltonian, describing interaction a single cavity mode and two-level atom without rotating wave approximation, subjected to damping dephasing reservoirs included via usual Lindblad superoperators in master equation. show that combination antirotating term atomic leads linear asymptotic photons generation from vacuum. reveal origins phenomenon estimate its importance realistic situations.
We study the all-optical control of quantum fluctuations a light beam via combination single-atom cavity electrodynamics (CQED) and electromagnetically induced transparency (EIT). Specifically, EIT field is used to tune CQED transition frequencies in out resonance with probe light. In this way, photon blockade antiblockade effects are employed produce sub-Poissonian super-Poissonian fields, respectively. The achievable paves way towards realization prototype novel transistor which amplifies...
Dipole-dipole interactions are at the origin of long-lived collective atomic states, often called subradiant, which explored for their potential use in novel photonic devices or quantum protocols. Here, we study subradiance beyond single-excitation regime and experimentally demonstrate a 200-fold increase population these modes, as saturation parameter driving field is increased. We attribute this enhancement to mechanism similar optical pumping through well-coupled superradiant states. The...
Two-photon interference is an indispensable resource in quantum photonics, but it not straightforward to achieve. The cascaded generation of photon pairs contains intrinsic temporal correlations that negatively affect the ability such sources perform two-photon interference, thus hindering applications. We report on how correlation interplays with decoherence and postselection, under which conditions postselection could improve visibility. Our study identifies crucial parameters points way a...
Systems of interacting classical harmonic oscillators have received considerable attention in the past years as analog models for describing electromagnetically induced transparency (EIT) and associated phenomena. We review these investigate their validity a variety physical systems using two three coupled oscillators. From simplest EIT-$\mathrm{\ensuremath{\Lambda}}$ configuration single cavity modes we show that each atomic dipole-allowed transition mode can be represented by damped...
The multiphoton Jaynes-Cummings model is investigated and applications in quantum information science are explored. Considering the strong atom-field coupling regime an $N$-photon interaction, a nonlinear driving field can perform arbitrary rotation Fock space of bosonic mode involving vacuum $M$-Fock state, with $M<N$. In addition, linear coherent (superposition many states), only cavity states within subspace ${|0⟩,|1⟩,\dots{},|N\ensuremath{-}1⟩}$ be populated; i.e., we show how to...
We investigate superpositions of two-mode squeezed states (TMSSs), which have potential applications in quantum information processing and sensing. study some properties these nonclassical such as the statistics each mode degree entanglement between two modes, can be higher than that a TMSS with same squeezing. The we consider prepared by inducing Jaynes-Cummings anti-Jaynes-Cummings interactions system modes spin-$\frac{1}{2}$ particle, for instance, trapped ion domain, described here. show...
In this Brief Report we present a scheme for the implementation of frequency up- and down-conversion operations in two-mode cavity quantum electrodynamics (QED). This protocol engineering bilinear interactions could enlarge perspectives quantum-information manipulation also be employed fundamental tests theory QED. As an application show how to generate squeezed state QED (the original entangled Einstein, Podolsky, Rosen).
In this work we show how to engineer bilinear and quadratic Hamiltonians in cavity quantum electrodynamics through the interaction of a single driven two-level atom with modes. The validity engineered is numerically analyzed even when considering effects both dissipative mechanisms, field atom. present scheme can be used, optical microwave regimes, for state preparation, implementation logical operations, fundamental tests theory.
In this Letter we extend current perspectives in engineering reservoirs by producing a time-dependent master equation leading to nonstationary superposition equilibrium state that can be nonadiabatically controlled the system-reservoir parameters. Working with an ion trapped inside nonideal cavity, first engineer effective interactions, which allow us achieve two classes of decoherence-free evolution superpositions ground and excited ionic levels: those azimuthal or polar angle. As...
Considering the paradigmatic case of a cloud two-level atoms interacting through common vacuum modes, we show how cooperative spontaneous emission, which is at origin superradiance, leads system to long-lived entangled states late times. These subradiant modes are characterized by an entanglement between all particles, independently their geometrical configuration. While there no threshold on interaction strength necessary entangle stronger interactions lead longer-lived entanglement.
We propose a scheme to dissipatively produce steady-state entanglement in two-qubit system, via an interaction with bosonic mode. The system is driven into stationary entangled state, while we compensate the mode dissipation by injecting energy coherent pump field. also present which allows us adiabatically transfer all population desired state. dynamics leading state these schemes can be understood analogy electromagnetically induced transparency and stimulated Raman adiabatic passage, respectively.
We theoretically investigate the implementation of a quantum controlled-phase gate in system constituted by single atom inside an optical cavity, based on electromagnetically induced transparency effect. First we show that probe pulse can experience $\ensuremath{\pi}$ phase shift due to presence or absence classical control field. Considering interplay cavity-EIT effect and memory process, demonstrated between two photons. To this end, first one needs store (control) photon ground atomic...
A recent work [Pegg et al., Phys. Rev. Lett. 81, 1604 (1998)] showed how to generate a running-wave superposition of zero- and one-photon field states, ${C}_{0}|0〉{+C}_{1}|1〉,$ by physical truncation the photon number making up coherent state. Here we discuss extension this device case N components: ${C}_{0}|0〉{+C}_{1}|1〉+\ensuremath{\cdot}\ensuremath{\cdot}\ensuremath{\cdot}{+C}_{N}|N〉.$
We show how to teleport a running wave superposition of zero- and one-photon field state through the projection synthesis technique. The fidelity scheme is computed taking into account noise introduced by dissipation efficiency detectors. These error sources have been single general relationship between input output operators.
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Eden Figueroa, Martin Mücke, Joerg Bochmann, Carolin Hahn, Karim Murr, Stephan Ritter, Celso J. Villas‐Boas, Gerhard Rempe; Electromagnetically Induced Transparency with Single Atoms in a Cavity. AIP Conf. Proc. 14 October 2011; 1363 (1): 389–392. https://doi.org/10.1063/1.3630217 Download citation file: Ris...
We study the dynamics of a two-level atom interacting with Lorentzian structured reservoir considering initial system-environment correlations. It is shown that under strong system-reservoir coupling purity can determine whether there are correlations between system and environment. Moreover, we investigate interaction two atoms same reservoir. In this case, show besides determining if correlations, atomic allows identification distinct correlated states. addition, quantum classical analyzed.
We investigate the quantum-to-classical crossover of a dissipative cavity field by measuring correlations between two noninteracting atoms coupled to mode. First, we note that there is time window in which mode shows classical behavior, depends on decay rate, atom-field coupling strength, and number atoms. Then, considering steady state inside cavity, entanglement disappears while mean photons ($\overline{n}$) rises. However, quantum discord reaches an asymptotic nonzero value even limit...