130 citations · 838 across the 27 of their papers we have counts for
24 papers · 1 filter
Automatic design of quantum feature maps
Sergio Altares-López, Angela Ribeiro, Juan José García-Ripoll
We propose a new technique for the automatic generation of optimal ad-hoc ansätze for classification by using quantum support vector machine (QSVM). This efficient method is based…
Quantum variational optimization: The role of entanglement and problem hardness
Pablo Díez-Valle, Diego Porras, Juan José García-Ripoll
Quantum variational optimization has been posed as an alternative to solve optimization problems faster and at a larger scale than what classical methods allow. In this paper we st…
Topological input-output theory for directional amplification
Tomás Ramos, Juan José García-Ripoll, Diego Porras
We present a topological approach to the input-output relations of photonic driven-dissipative lattices acting as directional amplifiers. Our theory relies on a mapping from the op…
Gaussian phase sensitivity of boson-sampling-inspired strategies
Antonio A. Valido, Juan José García-Ripoll
In this work we study the phase sensitivity of generic linear interferometric schemes using Gaussian resources and measurements. Our formalism is based on the Fisher information. T…
Scalable multiphoton generation from cavity-synchronized single-photon sources
Ming Li, Juan José García-Ripoll, Tomás Ramos
We propose an efficient, scalable, and deterministic scheme to generate multiple indistinguishable photons over independent channels, on demand. Our design relies on multiple singl…
Hybrid quantum-classical optimization for financial index tracking
Samuel Fernández-Lorenzo, Diego Porras, Juan José García-Ripoll
Tracking a financial index boils down to replicating its trajectory of returns for a well-defined time span by investing in a weighted subset of the securities included in the benc…
Remote Individual Addressing of Quantum Emitters with Chirped Pulses
Silvia Casulleras, Carlos Gonzalez-Ballestero, Patrick Maurer +2
We propose to use chirped pulses propagating near a bandgap to remotely address quantum emitters. We introduce a particular family of chirped pulses that dynamically self-compress…
Quantum control of frequency tunable transmon superconducting qubits
J. J. García-Ripoll, A. Ruiz-Chamorro, E. Torrontegui
In this work we analyze the implementation of a control-phase gate through the resonance between the and states of two statically coupled transmons. We fi…
Visualizing the emission of a single photon with frequency and time resolved spectroscopy
Aleksei Sharafiev, Mathieu L. Juan, Oscar Gargiulo +4
At the dawn of Quantum Physics, Wigner and Weisskopf obtained a full analytical description (a \textit{photon portrait}) of the emission of a single photon by a two-level system, u…
Quantum-inspired algorithms for multivariate analysis: from interpolation to partial differential equations
Juan José García-Ripoll
In this work we study the encoding of smooth, differentiable multivariate functions in quantum registers, using quantum computers or tensor-network representations. We show that a…
Quantum annealing in spin-boson model: from a perturbative to a ultrastrong mediated coupling
Manuel Pino, Juan José García-Ripoll
We study a quantum annealer where bosons mediate the Ising-type interactions between qubits. We compare the efficiency of ground state preparation for direct and mediated couplings…
Ultrastrongly dissipative quantum Rabi model
David Zueco, Juanjo García-Ripoll
We discuss the equilibrium and out of equilibrium dynamics of cavity QED in presence of dissipation beyond the standard perturbative treatment of losses. Using the dynamical polaro…
Correlated Dephasing Noise in Single-photon Scattering
Tomás Ramos, Juan José García-Ripoll
We develop a theoretical framework to describe the scattering of photons against a two-level quantum emitter with arbitrary correlated dephasing noise. This is particularly relevan…
Quantum Emulation of Molecular Force Fields: A Blueprint for a Superconducting Architecture
Diego G. Olivares, Borja Peropadre, Joonsuk Huh +1
In this work, we propose a flexible architecture of microwave resonators with tunable couplings to perform quantum simulations of problems from the field of molecular chemistry. Th…
Quantum Simulation with a Boson Sampling Circuit
Diego G. Olivares, Borja Peropadre, Alán Aspuru-Guzik +1
In this work we study a system that consists of matter qubits that interact through a boson sampling circuit, i.e., an -port interferometer, embedded in two different archi…
One- and two-photon scattering from generalized V-type atoms
Eduardo Sánchez-Burillo, Luis Martín-Moreno, David Zueco +1
The one- and two-photon scattering matrix S is obtained analytically for a one-dimensional waveguide and a point-like scatterer with N excited levels (generalized V -type atom). We…
Dynamical polaron ansatz: a theoretical tool for the ultra-strong coupling regime of circuit QED
Guillermo Díaz-Camacho, Alejandro Bermudez, Juan José García-Ripoll
In this work we develop a semi-analytical variational ansatz to study the properties of few photon excitations interacting with a collection of quantum emitters in regimes that go…
Stationary discrete solitons in circuit QED
Uta Naether, Fernando Quijandría, Juan José García-Ripoll +1
We demonstrate that stationary localized solutions (discrete solitons) exist in a one dimensional Bose-Hubbard lattices with gain and loss in the semiclassical regime. Stationary s…
Continuous matrix product states for coupled fields: Application to Luttinger Liquids and quantum simulators
Fernando Quijandría, Juan José García-Ripoll, David Zueco
A way of constructing continuous matrix product states (cMPS) for coupled fields is presented here. The cMPS is a variational \emph{ansatz} for the ground state of quantum field th…
Scattering in the ultrastrong regime: nonlinear optics with one photon
Eduardo Sánchez-Burillo, David Zueco, Juanjo García-Ripoll +1
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 a…
Lieb-Robinson bounds for spin-boson lattice models and trapped ions
J. Juenemann, A. Cadarso, D. Perez-Garcia +2
We derive a Lieb-Robinson bound for the propagation of spin correlations in a model of spins interacting through a bosonic lattice field, which satisfies itself a Lieb-Robinson bou…
Generating and verifying graph states for fault-tolerant topological measurement-based quantum computing in 2D optical lattices
Jaewoo Joo, Emilio Alba, Juan José García-Ripoll +1
We propose two schemes for implementing graph states useful for fault-tolerant topological measurement-based quantum computation in 2D optical lattices. We show that bilayer cluste…
Microwave photonics with Josephson junction arrays: negative refraction index and entanglement through disorder
David Zueco, Juan José Mazo, Enrique Solano +1
We study different architectures for a photonic crystal in the microwave regime based on superconducting transmission lines interrupted by Josephson junctions, both in one and two…
Detecting ground state qubit self-excitations in circuit QED: slow quantum anti-Zeno effect
C. Sabín, J. León, J. J. García-Ripoll
In this work we study an ultrastrong coupled qubit-cavity system subjected to slow repeated measurements. We demonstrate that even under a few imperfect measurements it is possible…