Publications (145)
Optimisation of ultrafast singlet fission in 1D rings towards unit efficiency
Francesco Campaioli, Alice Pagano, Daniel Jaschke +1
Singlet fission (SF) is an electronic transition that in the last decade has been under the spotlight for its applications in optoelectronics, from photovoltaics to spintronics. De…
Quantum circuit compilation with quantum computers
Davide Rattacaso, Daniel Jaschke, Marco Ballarin +2
Compilation optimizes quantum algorithms performances on real-world quantum computers. To date, it is performed via classical optimization strategies. We introduce a class of quant…
Optimal control transport of neutral atoms in optical tweezers at finite temperature
Alice Pagano, Daniel Jaschke, Werner Weiss +1
The transport of neutral atoms in Rydberg quantum computers is a crucial step of the initial arrangement of the grid as well as to the dynamic connectivity, recently successfully d…
Superradiant decay in non-Markovian Waveguide Quantum Electrodynamics
Rosa Lucia Capurso, Giuseppe Calajó, Simone Montangero +5
An array of initially excited emitters coupled to a one-dimensional waveguide exhibits superradiant decay under the Born-Markov approximation, manifested as a coherent burst of pho…
Random layers for quantum optimal control with exponential expressivity
Marco Dall'Ara, Martin Koppenhöfer, Florentin Reiter +3
A long-standing problem in quantum optimal control is finding an optimal pulse structure that leads to an efficient exploration of the unitary space with a minimal number of optimi…
Universal quantum computation in integrable systems
Seth Lloyd, Simone Montangero
Quantized integrable systems can be made to perform universal quantum computation by the application of a global time-varying control. The action-angle variables of the integrable…
Strongly interacting photons in 2D waveguide QED
Matija TeÄer, Marco Di Liberto, Pietro Silvi +3
One dimensional confinement in waveguide Quantum Electrodynamics (QED) plays a crucial role to enhance light-matter interactions and to induce a strong quantum nonlinear optical re…
Hadrons in (1+1)D Hamiltonian hardcore lattice QCD
Marco Rigobello, Giuseppe Magnifico, Pietro Silvi +1
We study 2-flavor Hamiltonian lattice QCD in (1+1)D with hardcore gluons, at zero and finite density, by means of matrix product states. We introduce a formulation of the theory wh…
Entangled quantum cellular automata, physical complexity, and Goldilocks rules
Logan E. Hillberry, Matthew T. Jones, David L. Vargas +6
Cellular automata are interacting classical bits that display diverse emergent behaviors, from fractals to random-number generators to Turing-complete computation. We discover that…
Simulating (2+1)D SU(2) Yang-Mills Lattice Gauge Theory at finite density with tensor networks
Giovanni Cataldi, Giuseppe Magnifico, Pietro Silvi +1
We numerically simulate a non-Abelian lattice gauge theory in two spatial dimensions, with tensor networks (TN), up to intermediate sizes (>30 matter sites) well beyond exact diago…
Kibble-Zurek scaling of the one-dimensional Bose-Hubbard model at finite temperatures
Werner Weiss, Matthias Gerster, Daniel Jaschke +2
We use tensor network methods - Matrix Product States, Tree Tensor Networks, and Locally Purified Tensor Networks - to simulate the one dimensional Bose-Hubbard model for zero and…
Optimal sampling of tensor networks targeting wave function's fast decaying tails
Marco Ballarin, Pietro Silvi, Simone Montangero +1
We introduce an optimal strategy to sample quantum outcomes of local measurement strings for isometric tensor network states. Our method generates samples based on an exact cumulat…
Phase Diagram and Conformal String Excitations of Square Ice using Gauge Invariant Matrix Product States
Ferdinand Tschirsich, Simone Montangero, Marcello Dalmonte
We investigate the ground state phase diagram of square ice -- a U(1) lattice gauge theory in two spatial dimensions -- using gauge invariant tensor network techniques. By correlat…
Crossover from the classical to the quantum Kibble-Zurek scaling
Pietro Silvi, Giovanna Morigi, Tommaso Calarco +1
The Kibble-Zurek (KZ) hypothesis identifies the relevant time scales in out-of-equilibrium dynamics of critical systems employing concepts valid at equilibrium: It predicts the sca…
Dynamically localized systems: entanglement exponential sensitivity and efficient quantum simulations
Simone Montangero
We study the pairwise entanglement present in a quantum computer that simulates a dynamically localized system. We show that the concurrence is exponentially sensitive to changes i…
Full characterization of the quantum linear-zigzag transition in atomic chains
Pietro Silvi, Gabriele De Chiara, Tommaso Calarco +2
A string of repulsively interacting particles exhibits a phase transition to a zigzag structure, by reducing the transverse trap potential or the interparticle distance. The transi…
Dressing the chopped-random-basis optimization: a bandwidth-limited access to the trap-free landscape
Niklas Rach, Matthias M. Müller, Tommaso Calarco +1
In quantum optimal control theory the success of an optimization algorithm is highly influenced by how the figure of merit to be optimized behaves as a function of the control fiel…
Quantum Billiards in Optical Lattices
Simone Montangero, Diego Frustaglia, Tommaso Calarco +1
We study finite two dimensional spin lattices with definite geometry (spin billiards) demonstrating the display of collective integrable or chaotic dynamics depending on their shap…
Entanglement generation in QED scattering processes
Marco Rigobello, Simone Notarnicola, Giuseppe Magnifico +1
We study real-time meson-meson scattering processes in -dimensional QED by means of Tensor Networks. We prepare initial meson wave packets with given momentum and position i…
One decade of quantum optimal control in the chopped random basis
Matthias M. Müller, Ressa S. Said, Fedor Jelezko +2
The Chopped RAndom Basis (CRAB) ansatz for quantum optimal control has been proven to be a versatile tool to enable quantum technology applications, quantum computing, quantum simu…
Macroscopic Hyperpolarization Enhanced with Quantum Optimal Control
Alastair Marshall, Thomas Reisser, Phila Rembold +13
Hyperpolarization of nuclear spins enhances nuclear magnetic resonance signals, which play a key role for imaging and spectroscopy in the natural and life sciences. This signal amp…
Communication at the quantum speed limit along a spin chain
Michael Murphy, Simone Montangero, Vittorio Giovannetti +1
Spin chains have long been considered as candidates for quantum channels to facilitate quantum communication. We consider the transfer of a single excitation along a spin-1/2 chain…
Entanglement in the Quantum Game of Life
Peter-Maximilian Ney, Simone Notarnicola, Simone Montangero +1
We investigate the quantum dynamics of a spin chain that implements a quantum analog of Conway's game of life. We solve the time-dependent Schrödinger equation starting with initi…
From classical to quantum criticality
Daniel Podolsky, Efrat Shimshoni, Pietro Silvi +4
We study the crossover from classical to quantum phase transitions at zero temperature within the framework of theory. The classical transition at zero temperature can be de…
Optimized Cooper pair pumps
Shabnam Safaei, Simone Montangero, Fabio Taddei +1
In adiabatic Cooper pair pumps, operated by means of gate voltage modulation only, the quantization of the pumped charge during a cycle is limited due to the quantum coherence of t…
The Augmented Tree Tensor Network Cookbook
Nora ReiniÄ, Luka PaveÅ¡iÄ, Daniel Jaschke +1
An augmented tree tensor network (aTTN) is a tensor network ansatz constructed by applying a layer of unitary disentanglers to a tree tensor network. The disentanglers absorb a par…
Quantum-inspired Machine Learning on high-energy physics data
Timo Felser, Marco Trenti, Lorenzo Sestini +4
Tensor Networks, a numerical tool originally designed for simulating quantum many-body systems, have recently been applied to solve Machine Learning problems. Exploiting a tree ten…
Simulation of time evolution with the MERA
Matteo Rizzi, Simone Montangero, Guifre' Vidal
We describe an algorithm to simulate time evolution using the Multi-scale Entanglement Renormalization Ansatz (MERA) and test it by studying a critical Ising chain with periodic bo…
Dynamical localization simulated on actual quantum hardware
Andrea Pizzamiglio, Su Yeon Chang, Maria Bondani +3
Quantum computers are invaluable tools to explore the properties of complex quantum systems. We show that dynamical localization of the quantum sawtooth map, a highly sensitive qua…
Towards Tensor Network Models for Low-Latency Jet Tagging on FPGAs
Alberto Coppi, Ema Puljak, Lorenzo Borella +6
We present a systematic study of Tensor Network (TN) models $\unicode{x2013}$ Matrix Product States (MPS) and Tree Tensor Networks (TTN) $\unicode{x2013}$ for real-time jet tagging…
Quantum algorithms for compact polymer thermodynamics
Davide Rattacaso, Daniel Jaschke, Antonio Trovato +2
Efficient sampling from ensembles of Hamiltonian cycles is critical for predicting the thermodynamic properties of compact polymers, with applications including modeling protein an…
Entanglement of formation of mixed many-body quantum states via Tree Tensor Operators
Luca Arceci, Pietro Silvi, Simone Montangero
We present a numerical strategy to efficiently estimate bipartite entanglement measures, and in particular the Entanglement of Formation, for many-body quantum systems on a lattice…
Violation of Bell inequalities in larger Hilbert spaces: robustness and challenges
Werner Weiss, Giuliano Benenti, Giulio Casati +4
We explore the challenges posed by the violation of Bell-like inequalities by -dimensional systems exposed to imperfect state-preparation and measurement settings. We address, i…
Robust Magnetometry with Single NV Centers via Two-step Optimization
Nimba Oshnik, Phila Rembold, Tommaso Calarco +3
Shallow Nitrogen-Vacancy (NV) centers are promising candidates for high-precision sensing applications; these defects, when positioned a few nanometers below the surface, provide a…
Ab-initio tree-tensor-network digital twin for quantum computer benchmarking in 2D
Daniel Jaschke, Alice Pagano, Sebastian Weber +1
Large-scale numerical simulations of the Hamiltonian dynamics of a Noisy Intermediate Scale Quantum (NISQ) computer - a digital twin - could play a major role in developing efficie…
Phase transitions in quantum-circuit compilation
Andrea De Girolamo, Davide Rattacaso, Simone Notarnicola +2
Quantum-circuit compilation aims at finding an optimized realization of a target circuit under given constraints, e.g., the minimization of hardware-induced errors and the unitary-…
Generation and manipulation of Schrödinger cat states in Rydberg atom arrays
Ahmed Omran, Harry Levine, Alexander Keesling +16
Quantum entanglement involving coherent superpositions of macroscopically distinct states is among the most striking features of quantum theory, but its realization is challenging,…
Finite-temperature Rydberg arrays: quantum phases and entanglement characterization
Nora ReiniÄ, Daniel Jaschke, Darvin Wanisch +2
As one of the most prominent platforms for analog quantum simulators, Rydberg atom arrays are a promising tool for exploring quantum phases and transitions. While the ground state…
Efficient Tensor Network ansatz for high-dimensional quantum many-body problems
Timo Felser, Simone Notarnicola, Simone Montangero
We introduce a novel tensor network structure augmenting the well-established Tree Tensor Network representation of a quantum many-body wave function. The new structure satisfies t…
Dynamical localization simulated on a few qubits quantum computer
Giuliano Benenti, Giulio Casati, Simone Montangero +1
We show that a quantum computer operating with a small number of qubits can simulate the dynamical localization of classical chaos in a system described by the quantum sawtooth map…
Color code thresholds under circuit-level noise beyond the Pauli framework
Francesco Pio Barone, Daniel Jaschke, Ilaria Siloi +1
A quantum error correction code is assessed over its ability to correct errors in noisy quantum circuits. This task requires extensive simulations of faulty quantum circuits, which…
Quantum Speed Limit and Optimal Control of Many-Boson Dynamics
Ioannis Brouzos, Alexej I. Streltsov, Antonio Negretti +4
We extend the concept of quantum speed limit -- the minimal time needed to perform a driven evolution -- to complex interacting many-body systems. We investigate a prototypical man…
Dynamics of entanglement in quantum computers with imperfections
Simone Montangero, Giuliano Benenti, Rosario Fazio
The dynamics of the pairwise entanglement in a qubit lattice in the presence of static imperfections exhibits different regimes. We show that there is a transition from a perturbat…
Local shortcut to adiabaticity for quantum many-body systems
Victor Mukherjee, Simone Montangero, Rosario Fazio
We study the environment assisted local transitionless dynamics in closed spin systems driven through quantum critical points. In general shortcut to adaiabaticity (STA) in quantum…
QuOCS: The Quantum Optimal Control Suite
Marco Rossignolo, Thomas Reisser, Alastair Marshall +9
Quantum optimal control includes the family of pulse-shaping algorithms that aim to unlock the full potential of a variety of quantum technologies. Our Quantum Optimal Control Suit…
Spin chain model for correlated quantum channels
Davide Rossini, Vittorio Giovannetti, Simone Montangero
We analyze the quality of the quantum information transmission along a correlated quantum channel by studying the average fidelity between input and output states and the average o…
Realistic and verifiable coherent control of excitonic states in a light harvesting complex
Stephan Hoyer, Filippo Caruso, Simone Montangero +4
We explore the feasibility of coherent control of excitonic dynamics in light harvesting complexes, analyzing the limits imposed by the open nature of these quantum systems. We est…
Digital quantum simulation of lattice fermion theories with local encoding
Marco Ballarin, Giovanni Cataldi, Giuseppe Magnifico +5
We numerically analyze the feasibility of a platform-neutral, general strategy to perform quantum simulations of fermionic lattice field theories under open boundary conditions. Th…
Density-of-states of many-body quantum systems from tensor networks
Fabian Schrodi, Pietro Silvi, Ferdinand Tschirsich +2
We present a technique to compute the microcanonical thermodynamical properties of a manybody quantum system using tensor networks. The Density Of States (DOS), and more general sp…
Transport properties of a periodically driven superconducting single electron transistor
Alessandro Romito, Simone Montangero, Rosario Fazio
We discuss coherent transport of Cooper pairs through a Cooper pair shuttle. We analyze both the DC and AC Josephson effect in the two limiting cases where the charging energy $E_C…
Introduction to Quantum Optimal Control for Quantum Sensing with Nitrogen-Vacancy Centers in Diamond
Phila Rembold, Nimba Oshnik, Matthias M. Müller +3
Diamond based quantum technology is a fast emerging field with both scientific and technological importance. With the growing knowledge and experience concerning diamond based quan…
One-dimensional many-body entangled open quantum systems with tensor network methods
Daniel Jaschke, Simone Montangero, Lincoln D. Carr
We present a collection of methods to simulate entangled dynamics of open quantum systems governed by the Lindblad equation with tensor network methods. Tensor network methods usin…
Is quantum computing green? An estimate for an energy-efficiency quantum advantage
Daniel Jaschke, Simone Montangero
The quantum advantage threshold determines when a quantum processing unit (QPU) is more efficient with respect to classical computing hardware in terms of algorithmic complexity. T…
Optimal local basis truncation of lattice quantum many-body systems
Peter Majcen, Giovanni Cataldi, Pietro Silvi +1
We show how to optimally reduce the local Hilbert basis of lattice quantum many-body (QMB) Hamiltonians. The basis truncation exploits the most relevant eigenvalues of the estimate…
Many-body quantum dimerization in 2D atomic arrays
Giuseppe Calajò, Matija TeÄer, Simone Montangero +2
We consider a 2D atomic array coupled to different photonic environments, focusing on the half-filled excitation subspace, where strong photon interactions can give rise to complex…
Integer Factorization via Tensor Network Schnorr's Sieving
Marco Tesoro, Ilaria Siloi, Daniel Jaschke +2
Classical public-key cryptography standards rely on the Rivest-Shamir-Adleman (RSA) encryption protocol. The security of this protocol is based on the exponential computational com…
Scattering and induced false vacuum decay in the two-dimensional quantum Ising model
Luka PaveÅ¡iÄ, Marco Di Liberto, Simone Montangero
We study scattering in the quantum Ising model in two dimensions. In the ordered phase, the spectrum contains a ladder of bound states and intertwined scattering resonances, which…
Observable Estimation in the Absence of Classical Verification
Samantha V. Barron, Bradley Mitchell, Vinay Tripathi +45
The paper proposes a framework to independently validate observable estimates from quantum computers when classical benchmarks are unavailable, using experiments such as the operat…
Digital quantum simulation of a (1+1)D SU(2) lattice gauge theory with ion qudits
Giuseppe Calajò, Giuseppe Magnifico, Claire Edmunds +3
We present a quantum simulation strategy for a (1+1)D SU(2) non-abelian lattice gauge theory with dynamical matter, a hardcore-gluon Hamiltonian Yang-Mills, tailored to a six-level…
A Set of Annealing Protocols for Optimized System Dynamics and Classification of Fully Connected Spin Glass Problems
Gino Bishop, Simone Montangero, Frank K. Wilhelm
We perform exact diagonalization and time evolution of the Lechner-Hauke-Zoller (LHZ) annealing architecture [Science Advances 1(9), e1500838 (2015)] for ten physical qubits. There…
Optimal control of Rydberg lattice gases
Jian Cui, Rick van Bijnen, Thomas Pohl +2
We present optimal control protocols to prepare different many-body quantum states of Rydberg atoms in optical lattices. Specifically, we show how to prepare highly ordered many-bo…
Ab-initio characterization of the quantum linear-zigzag transition using DMRG
Pietro Silvi, Tommaso Calarco, Giovanna Morigi +1
Ions of the same charge inside confining potentials can form crystalline structures which can be controlled by means of the ions density and of the external trap parameters. In par…
Optimized single-qubit gates for Josephson phase qubits
Shabnam Safaei, Simone Montangero, Fabio Taddei +1
In a Josephson phase qubit the coherent manipulations of the computational states are achieved by modulating an applied ac current, typically in the microwave range. In this work w…
Multipartite entanglement generation and fidelity decay in disordered qubit systems
Simone Montangero, Lorenza Viola
We investigate multipartite entanglement dynamics in disordered spin-1/2 lattice models exhibiting a transition from integrability to quantum chaos. Borrowing from the recently int…
Real-time-dynamics quantum simulation of (1+1)-D lattice QED with Rydberg atoms
Simone Notarnicola, Mario Collura, Simone Montangero
We show how to implement a Rydberg-atom quantum simulator to study the non-equilibrium dynamics of an Abelian (1+1)-D lattice gauge theory. The implementation locally codifies the…
Eigenstates of Operating Quantum Computer: Hypersensitivity to Static Imperfections
Giuliano Benenti, Giulio Casati, Simone Montangero +1
We study the properties of eigenstates of an operating quantum computer which simulates the dynamical evolution in the regime of quantum chaos. Even if the quantum algorithm is pol…
Dynamical Imperfections in quantum computers
Paolo Facchi, Simone Montangero, Rosario Fazio +1
We study the effects of dynamical imperfections in quantum computers. By considering an explicit example, we identify different regimes ranging from the low-frequency case, where t…
Entanglement transitions in a boundary-driven open quantum many-body system
Darvin Wanisch, Nora ReiniÄ, Daniel Jaschke +2
We introduce a numerical framework for integrating Markovian dynamics on tree tensor operator (TTO) ansatz states. This framework enables the simulation of both transient and stead…
Quantum Computing for High-Energy Physics: State of the Art and Challenges. Summary of the QC4HEP Working Group
Alberto Di Meglio, Karl Jansen, Ivano Tavernelli +43
Quantum computers offer an intriguing path for a paradigmatic change of computing in the natural sciences and beyond, with the potential for achieving a so-called quantum advantage…
Quantum computing and information extraction for a dynamical quantum system
Giuliano Benenti, Giulio Casati, Simone Montangero
We discuss the simulation of a complex dynamical system, the so-called quantum sawtooth map model, on a quantum computer. We show that a quantum computer can be used to efficiently…
Quantum optimal control in quantum technologies. Strategic report on current status, visions and goals for research in Europe
Christiane P. Koch, Ugo Boscain, Tommaso Calarco +8
Quantum optimal control, a toolbox for devising and implementing the shapes of external fields that accomplish given tasks in the operation of a quantum device in the best way poss…
Superfluid to Mott transition in a Bose-Hubbard ring: Persistent currents and defect formation
Lucas Kohn, Pietro Silvi, Matthias Gerster +4
We revisit here the Kibble-Zurek mechanism for superfluid bosons slowly driven across the transition towards the Mott-insulating phase. By means of a combination of the Time-Depend…
Towards an experimentally feasible controlled-phase gate on two blockaded Rydberg atoms
Matthias M. Müller, Michael Murphy, Simone Montangero +3
We investigate the implementation of a controlled-Z gate on a pair of Rydberg atoms in spatially separated dipole traps where the joint excitation of both atoms into the Rydberg le…
Tensor Network Simulation of compact one-dimensional lattice Quantum Chromodynamics at finite density
Pietro Silvi, Yannick Sauer, Ferdinand Tschirsich +1
We perform a zero temperature analysis of a non-Abelian lattice gauge model corresponding to an SU(3) Yang Mills theory in 1+1D at low energies. Specifically, we characterize the m…
Phase diagram of spin-1 bosons on one-dimensional lattices
Matteo Rizzi, Davide Rossini, Gabriele De Chiara +2
Spinor Bose condensates loaded in optical lattices have a rich phase diagram characterized by different magnetic order. Here we apply the Density Matrix Renormalization Group to ac…
Adaptive-weighted tree tensor networks for disordered quantum many-body systems
Giovanni Ferrari, Giuseppe Magnifico, Simone Montangero
We introduce an adaptive-weighted tree tensor network, for the study of disordered and inhomogeneous quantum many-body systems. This ansatz is assembled on the basis of the random…
Speeding up and slowing down the relaxation of a qubit by optimal control
Victor Mukherjee, Alberto Carlini, Andrea Mari +5
We consider a two-level quantum system prepared in an arbitrary initial state and relaxing to a steady state due to the action of a Markovian dissipative channel. We study how opti…
Two-dimensional quantum-link lattice Quantum Electrodynamics at finite density
Timo Felser, Pietro Silvi, Mario Collura +1
We present an unconstrained tree tensor network approach to the study of lattice gauge theories in two spatial dimensions showing how to perform numerical simulations of theories i…
Quantum algorithms for equational reasoning
Davide Rattacaso, Daniel Jaschke, Marco Ballarin +2
As a cornerstone of automated reasoning, equational reasoning finds equivalences between symbolic expressions and fuels advances across scientific disciplines. Yet, its potential r…
Superfluid density and quasi-long-range order in the one-dimensional disordered Bose-Hubbard model
Matthias Gerster, Matteo Rizzi, Ferdinand Tschirsich +3
We study the equilibrium properties of the one-dimensional disordered Bose-Hubbard model by means of a gauge-adaptive tree tensor network variational method suitable for systems wi…
A quantum optical valve in a nonlinear-linear resonator junction
Eduardo Mascarenhas, Daniel Valente, Simone Montangero +3
Electronic diodes, which enable the rectification of an electrical energy flux, have played a crucial role in the development of current microelectronics after the invention of sem…
Fractal Fidelity as a signature of Quantum Chaos
Franco Pellegrini, Simone Montangero
We analyze the fidelity of a quantum simulation and we show that it displays fractal fluctuations iff the simulated dynamics is chaotic. This analysis allows us to investigate a gi…
Hilbert curve vs Hilbert space: exploiting fractal 2D covering to increase tensor network efficiency
Giovanni Cataldi, Ashkan Abedi, Giuseppe Magnifico +4
We present a novel mapping for studying 2D many-body quantum systems by solving an effective, one-dimensional long-range model in place of the original two-dimensional short-range…
Entanglement production in chaotic quantum dots subject to spin-orbit coupling
Diego Frustaglia, Simone Montangero, Rosario Fazio
We study numerically the production of orbital and spin entangled states in chaotic quantum dots for non-interacting electrons. The introduction of spin-orbit coupling permit us to…
Optimal Phonon-to-Spin Mapping in a system of a trapped ion
Matthias M. Müller, Ulrich G. Poschinger, Tommaso Calarco +2
We propose a protocol for measurement of the phonon number distribution of a harmonic oscillator based on selective mapping to a discrete spin-1/2 degree of freedom. We consider a…
A new rung on the ladder: exploring topological frustration towards two dimensions
Alberto Giuseppe Catalano, Nora ReiniÄ, Gianpaolo Torre +5
Topological frustration arises when boundary conditions impose geometric frustration in a quantum system, creating delocalized defects in the ground states and profoundly altering…
Optimizing for an arbitrary perfect entangler. II. Application
Michael H. Goerz, Giulia Gualdi, Daniel M. Reich +7
The difficulty of an optimization task in quantum information science depends on the proper mathematical expression of the physical target. Here we demonstrate the power of optimiz…
Decoherence by engineered quantum baths
Davide Rossini, Tommaso Calarco, Vittorio Giovannetti +2
We introduce, and determine decoherence for, a wide class of non-trivial quantum spin baths which embrace Ising, XY and Heisenberg universality classes coupled to a two-level syste…
Optimal preparation of quantum states on an atom chip device
Cosimo Lovecchio, Florian Schäfer, Shahid Cherukattil +6
Atom chips provide compact and robust platforms towards practical quantum technologies. A quick and faithful preparation of arbitrary input states for these systems is crucial but…
Chaotic dynamics in superconducting nanocircuits
Simone Montangero, Alessandro Romito, Giuliano Benenti +1
The quantum kicked rotator can be realized in a periodically driven superconducting nanocircuit. A study of the fidelity allows the experimental investigation of exponential instab…
Optimized state transfer in systems of ultrastrongly coupled matter and radiation
Luigi Giannelli, Jishnu Rajendran, Nicola Macrì +4
Ultrastrong coupling may allow faster operations for the development of quantum technologies at the expenses of increased sensitivity to new kind of intrinsic errors. We study stat…
Tensor Networks for Lattice Gauge Theories beyond one dimension: a Roadmap
Giuseppe Magnifico, Giovanni Cataldi, Marco Rigobello +4
Tensor network methods are a class of numerical tools and algorithms to study many-body quantum systems in and out of equilibrium, based on tailored variational wave functions. The…
The Tensor Networks Anthology: Simulation techniques for many-body quantum lattice systems
Pietro Silvi, Ferdinand Tschirsich, Matthias Gerster +4
We present a compendium of numerical simulation techniques, based on tensor network methods, aiming to address problems of many-body quantum mechanics on a classical computer. The…
Optimal control of many-body non-equilibrium quantum thermodynamics
Niklas Rach, Simone Montangero, Mauro Paternostro
We demonstrate the effectiveness of quantum optimal control techniques in harnessing irreversibility generated by non-equilibrium processes, implemented in unitarily evolving quant…
Dipole oscillations of confined lattice bosons in one dimension
Simone Montangero, Rosario Fazio, Peter Zoller +1
We study the dynamics of a non-integrable system comprising interacting cold bosons trapped in an optical lattice in one-dimension by means of exact time-dependent numerical DMRG t…
Demonstration of quantum brachistochrones between distant states of an atom
Manolo R. Lam, Natalie Peter, Thorsten Groh +7
Transforming an initial quantum state into a target state through the fastest possible route---a quantum brachistochrone---is a fundamental challenge for many technologies based on…
The Role of Bases in Quantum Optimal Control
Alice Pagano, Matthias M Müller, Tommaso Calarco +2
Quantum Optimal Control (QOC) supports the advance of quantum technologies by tackling its problems at the pulse level: Numerical approaches iteratively work towards a given target…
Adiabatic quenches through an extended quantum critical region
Franco Pellegrini, Simone Montangero, Giuseppe E. Santoro +1
By gradually changing the degree of the anisotropy in a XXZ chain we study the defect formation in a quantum system that crosses an extended critical region. We discuss two qualita…
Efficient Quantum Computing of Complex Dynamics
Giuliano Benenti, Giulio Casati, Simone Montangero +1
We propose a quantum algorithm which uses the number of qubits in an optimal way and efficiently simulates a physical model with rich and complex dynamics described by the quantum…
Efficiency of quantum controlled non-Markovian thermalization
Victor Mukherjee, Vittorio Giovannetti, Rosario Fazio +3
We study optimal control strategies to optimize the relaxation rate towards the fixed point of a quantum system in the presence of a non-Markovian dissipative bath. Contrary to nai…