Efficient quantum simulation of fermionic and bosonic models in trapped ions

We analyze the efficiency of quantum simulations of fermionic and bosonic models in trapped ions. In particular, we study the optimal time of entangling gates and the required number of total elementary gates. Furthermore, we exemplify these estimations in the light of quantum simulations of quantum field theories, condensed-matter physics, and quantum chemistry. Finally, we show that trapped-ion technologies are a suitable platform for implementing quantum simulations involving interacting fermionic and bosonic modes, paving the way for overcoming classical computers in the near future.Comment: 13 pages, 3 figures. Published in EPJ Quantum Technolog

The Off-forward Quark-Quark Correlation Function

The properties of the non-forward quark-quark correlation function are examined. We derive constraints on the correlation function from the transformation properties of the fundamental fields of QCD occurring in its definition. We further develop a method to construct an ansatz for this correlator. We present the complete leading order set of generalized parton distributions in terms of the amplitudes of the ansatz. Finally we conclude that the number of independent generalized parton helicity changing distributions is four.Comment: Accepted for publication in Physical Review

Quando a democracia incuba desigualdade e heteronomia: autoritarismo e nacionalismo na UE

In this study we analyse the social base of authoritarian and nationalist (AN) parties in the European Union grounded on a theory that articulates social and cultural dimensions. We aim to characterize and understand this electorate, and explain its increase, considering their social class, education, income, social orientations, human values, and attitudes towards immigrants, and looking upon the trajectory of inequalities. Data is from the European Social Survey and contextual national level information on economic and educational inequalities, and on social mobility. We find that AN parties voters are mostly industrial and agricultural workers, with very low educational resources and low income. They are characterized by the social orientation of heteronomy, a paradigmatic conformist disposition combining conformity with inequality and conformity with hetero-determination of one’s social position, here defined by a low score of the human values of equality and creativity. Heteronomy helps to understand a wide range of AN cultural traits of this population such as their exclusionary attitude towards immigrants. And we verify that the expansion of this electorate follows increasing inequality, mainly in education, as well as downward mobility, and social exclusion.info:eu-repo/semantics/publishedVersio

Quantum Simulation of Quantum Field Theories in Trapped Ions

We propose the quantum simulation of a fermion and an antifermion field modes interacting via a bosonic field mode, and present a possible implementation with two trapped ions. This quantum platform allows for the scalable add-up of bosonic and fermionic modes, and represents an avenue towards quantum simulations of quantum field theories in perturbative and nonperturbative regimes.Comment: To be published in Physical Review Letter

Quality of life, subjective well-being and democratic consolidation in Ecuador

The analysis of individual satisfaction and citizens’ quality of life is paramount by the interdependence with democracy consolidation that exists nowadays in Ecuador. A proposal to calculate a synthetic indicator of satisfaction of citizens on the subjective wellbeing (SWB) in Ecuador based on fuzzy logic method and the degree of similarity to ideal solutions is developed in the study. The information is obtained through the application of a structured survey based on the European Social Survey to the Ecuadorian society to a sample of 416 Ecuadorians. The analysis is based on eight different dimensions of individual satisfaction, namely: (1) Life; (2) Economy; (3) City Government; (4) Transparency; (5) Education; (6) Health System; (7) Roads; and (8) National Government. The results are discussed according to three segmentation variables: gender, age and marital status. The results show that men experience more individual satisfaction than women; generation Y is more satisfied than other age groups; and those who live with couples without being married are more satisfied than single and married citizens.info:eu-repo/semantics/acceptedVersio

Digital Quantum Simulation of the Holstein Model in Trapped Ions

We propose the implementation of the Holstein model by means of digital methods in a linear chain of trapped ions. We show how the simulation fidelity scales with the generation of phononic excitations. We propose a decomposition and a stepwise trapped-ion implementation of the Holstein Hamiltonian. Via numerical simulations, we study how the protocol is affected by realistic gates. Finally, we show how measurements of the size of the simulated polaron can be performed.Comment: 5 pages + supplemental material, 3+3 figures. Accepted in Physical Review Letter

Measurement-based adaptation protocol with quantum reinforcement learning in a Rigetti quantum computer

We present an experimental realization of a measurement-based adaptation protocol with quantum reinforcement learning in a Rigetti cloud quantum computer. The experiment in this few-qubit superconducting chip faithfully reproduces the theoretical proposal, setting the first steps towards a semiautonomous quantum agent. This experiment paves the way towards quantum reinforcement learning with superconducting circuits