41 citations · 461 across the 30 of their papers we have counts for
30 papers
Level crossings and superradiant quantum phase transition for a two-qutrit quantum Rabi model
R. Grimaudo, A. S. M. De Castro, G. Falci +3
A two-qutrit extension of the quantum Rabi model is studied. Despite its increased complexity, the model results to be integrable under specific, physically relevant conditions. Th…
Jaynes-Cummings dynamics in strong coupling for many-interacting-qubit quantum Rabi models
Roberto Grimaudo, Sagnik Chakraborty, Rosario Lo Franco +1
The present work focuses on the strong/weak interaction of many-body spin-systems with a cavity mode. It introduces the necessity of redefining the physical conditions determining…
Thermodynamic Limit in the Two-qubit Quantum Rabi Model with Spin-Spin Coupling
R. Grimaudo, G. Falci, A. Messina +4
The occurrence of a second-order superradiant quantum phase transition is brought to light in a quantum system consisting of two interacting qubits coupled to the same quantized fi…
Axion field influence on Josephson junction quasipotential
Roberto Grimaudo, Davide Valenti, Bernardo Spagnolo +3
The direct effect of an axion field on Josephson junctions is analyzed through the consequences on the effective potential barrier that prevents the junction from switching from th…
Quantum phase transitions for an integrable quantum Rabi-like model with two interacting qubits
Roberto Grimaudo, Antonio S. M. de Castro, Antonino Messina +2
A two-interacting-qubit quantum Rabi-like model with vanishing transverse fields on the qubit-pair is studied. Independently of the coupling regime, this model can be exactly and u…
Spin-spin coupling-based quantum and classical phase transitions in two-impurity spin-boson models
Roberto Grimaudo, Antonino Messina, Hiromichi Nakazato +2
The class of two-interacting-impurity spin-boson models with vanishing transverse fields on the spin-pair is studied. The model can be exactly mapped into two independent standard…
Axion-induced oscillations in Josephson qubits
Roberto Grimaudo, Claudio Guarcello, Giovanni Filatrella +2
An effective quantum description of the axion is proposed as a two-level dynamic system together with a spin-spin Hamiltonian for a coupled axion-Josephson qubit system. The intera…
Spin-chain-star systems: entangling multiple chains of spin qubits
R. Grimaudo, A. S. M. de Castro, A. Messina +1
We consider spin-chain-star systems characterized by N-wise many-body interactions between the spins in each chain and the central one. We show that such systems can be exactly map…
Josephson junction-based axion detection through resonant activation
Roberto Grimaudo, Davide Valenti, Bernardo Spagnolo +2
We discuss the resonant activation phenomenon on a Josephson junction due to the coupling of the Josephson system with axions. We show how such an effect can be exploited for axion…
Stochastic 0-dimensional Biogeochemical Flux Model: Effect of temperature fluctuations on the dynamics of the biogeochemical properties in a marine ecosystem
Paolo Lazzari, Roberto Grimaudo, Cosimo Solidoro +1
We present a new stochastic model, based on a 0-dimensional version of the well known biogeochemical flux model (BFM), which allows to take into account the temperature random fluc…
Greenberger-Horne-Zeilinger state generation in qubit-chains via a single -pulse
Roberto Grimaudo, Nikolay V. Vitanov, Antonio Sergio Magalaes de Castro +2
A protocol for generating Greenberger-Horne-Zeilinger states in a system of coupled qubits is proposed. The Hamiltonian model assumes -wise interactions between the qubi…
Dynamics of quantum discord of two coupled spin-1/2 subjected to time-dependent magnetic fields
Roberto Grimaudo, Tatiana Mihaescu, Aurelian Isar +2
We describe the dynamics of quantum discord of two interacting spin-1/2 subjected to controllable time-dependent magnetic fields. The exact time evolution of discord is given for v…
New approach to describe two coupled spins in a variable magnetic field
Yuri Belousov, Roberto Grimaudo, Antonino Messina +2
We propose a method to describe the evolution of two spins coupled by hyperfine interaction in an external time-dependent magnetic field. We apply the approach to the case of hyper…
Quantum Correlation Dynamics in Controlled Two-Coupled-Qubit Systems
Iulia Ghiu, Roberto Grimaudo, Tatiana Mihaescu +2
We study and compare the time evolutions of concurrence and quantum discord in a driven system of two interacting qubits prepared in a generic Werner state. The~corresponding quant…
Two-qubit entanglement generation through non-Hermitian Hamiltonians induced by repeated measurements on an ancilla
R. Grimaudo, A. Messina, A. Sergi +2
In contrast to classical systems, actual implementation of non-Hermitian Hamiltonian dynamics for quantum systems is a challenge because the processes of energy gain and dissipatio…
Dzyaloshinskii-Moriya and dipole-dipole interactions affect coupling-based Landau-Majorana-Stückelberg-Zener transitions
Roberto Grimaudo, Hiromichi Nakazato, Antonino Messina +1
It has been theoretically demonstrated that two spins (qubits or qutrits), coupled by exchange interaction only, undergo a coupling-based joint Landau-Majorana-Stückelberg-Zener (L…
Dynamics of a harmonic oscillator coupled with a Glauber amplifier
R. Grimaudo, V. I. Man'ko, M. A. Man'ko +1
A system of a quantum harmonic oscillator bi-linearly coupled with a Glauber amplifier is analysed considering a time-dependent Hamiltonian model. The Hilbert space of this system…
Proposal of a computational approach for simulating thermal bosonic fields in phase space
Alessandro Sergi, Roberto Grimaudo, Gabriel Hanna +1
When a quantum field is in contact with a thermal bath, the vacuum state of the field may be generalized to a thermal vacuum state, which takes into account the thermal noise. In t…
Analytically solvable -symmetry dynamics from su(1,1)-symmetry problems
R. Grimaudo, A. S. M. de Castro, H. Nakazato +1
A protocol for explicitly constructing the exact time-evolution operators generated by time-dependent -symmetry Hamiltonians is reported. Its mathematical applicab…
Landau-Majorana-Stuckelberg-Zener dynamics driven by coupling for two interacting qutrit systems
R. Grimaudo, N. V. Vitanov, A. Messina
A time-dependent two interacting spin-qutrit model is analysed and solved. The two interacting qutrits are subjected to a longitudinal field linearly varying over time as in the La…
Coupling-assisted Landau-Majorana-Stuckelberg-Zener transition in two-interacting-qubit systems
R. Grimaudo, N. V. Vitanov, A. Messina
We analyse a system of two interacting spin-qubits subjected to a Landau-Majorana-Stückelberg-Zener (LMSZ) ramp. We prove that LMSZ transitions of the two spin-qubits are possible…
Quasi-Lie Brackets and the Breaking of Time-Translation Symmetry for Quantum Systems Embedded in Classical Baths
Alessandro Sergi, Gabriel Hanna, Roberto Grimaudo +1
Many open quantum systems encountered in both natural and synthetic situations are embedded in classical-like baths. Often, the bath degrees of freedom may be represented in terms…
Exactly solvable time-dependent pseudo-Hermitian (1,1) Hamiltonian models
R. Grimaudo, A. S. M. de Castro, M. Kus +1
An exact analytical treatment of the dynamical problem for time-dependent 2x2 pseudo-hermitian su(1,1) Hamiltonians is reported. A class of exactly solvable and physically transpar…
Cooling of Many-Body Systems via Selective Interactions
R. Grimaudo, L. Lamata, E. Solano +1
We propose a model describing spin-1/2 systems coupled through -order homogeneous interaction terms, in presence of local time-dependent magnetic fields. This model can be e…