arXiv subjects

Francesco Perciavalle

Publications and source records attributed to Francesco Perciavalle.

12 recordsLinked to original sources

arXiv2026

Magic transfer in quantum spin chains

Quantum communication protocols based on spin chains have been extensively studied, yet their ability to transmit nonstabilizer resources has not been systematically addressed. We investigate the transport of quantum magic in spin chains through the natural dynamics of systems initialized in nonstabilizer states, and quantify the transported resource via the stabilizer norm. We analyze three experimentally feasible state-transfer protocols, ranging from noisy to (quasi-)perfect transfer, including one realizable in trapped-ion platforms. We find that the geometry of the injected state strongly influences transport: states in the lower Bloch hemisphere achieve higher transfer quality, whereas states in the upper hemisphere give rise to an efficient magic transport only beyond a threshold value of the parameter controlling the tendency towards perfect transfer. These features are robust across all protocols and identify the Hamiltonian and state properties that favor high-quality transfer. Moreover, we identify a parameter region, relevant to the initial state preparation, in which the transported magic exceeds the initial encoding, indicating that such spin systems can act as magic-amplification channels. Our results establish the conditions for efficient transport of nonstabilizer resources and demonstrate quantum magic as a sensitive probe of quantum transport beyond population dynamics.

quant-ph↗

arXiv2026

Phase-dependent role of dissipation across the Aubry-Andr\'e-Harper transition

We study transport across the Aubry-Andr\'e-Harper localization transition in the presence of non-Markovian dissipation. For a single particle initially at the center of the chain, we show that bath memory (i.e., finite decay time of bath correlations) plays distinct roles in the two phases. In the extended phase, bath memory qualitatively reshapes the dynamical generator, thereby producing transport patterns that cannot be reduced to a simple rescaling of time. By contrast, in the localized phase, the bath activates motion between localized states and bath memory mainly renormalizes the dynamical timescales. Our results identify localization as a simple filter of non-Markovian effects: memory restructures transport in the extended regime, but survives mainly as a timescale renormalization in the deeply localized regime.

quant-ph↗

arXiv2026

Floquet-engineered fidelity revivals in the PXP model

We explore the dynamics of the PXP model when subjected to a periodic drive, and unveil the mechanism through which the interplay between spectral properties and initial states governs the emergence of dynamical revivals and their evolution across the space of driving parameters. For N\'eel-ordered initial states, revivals follow well-defined trajectories in the parameter space of the driving, primarily determined by a dominant quasi-energy spacing in the Floquet spectrum. Initial states interpolating between N\'eel and fully polarized configurations exhibit hybrid dynamics, which can be controlled by tuning their overlap with Floquet eigenstates via the driving parameters. This control also allows steering different routes for avoiding Floquet thermalization, showing how both initial state choice and driving protocol shape long-lived dynamics in this driven quantum many-body systems.

quant-ph↗

arXiv2025

Local reminiscence in the PXP model

We study the emergence of local reminiscence in the PXP model, a constrained spin system realized in Rydberg atom arrays. The spectrum of this model is characterized by a majority of eigenstates that satisfy the eigenstate thermalization hypothesis, alongside a set of nonthermal eigenstates, known as quantum many-body scars, that violate it. While generic initial states lead to thermalization consistent with eigenstate thermalization hypothesis, special configurations generate non-ergodic dynamics and preserve memory of the initial state. In this work, we explore local memory retention using local fidelity and the dynamics of local observables. We find that two specific states, $\theta$-symmetric and blockaded states, exhibit robust local reminiscence, with fidelities near unity and suppressed fluctuations as the system size increases. Our results show that non-ergodic regimes can sustain stable local memory while still allowing for complex global dynamics, providing new insights into quantum many-body scars and constrained dynamics.

quant-ph↗

arXiv2025

Quantum Coherence and Anomalous Work Extraction in Qubit Gate Dynamics

We develop a framework based on the Kirkwood-Dirac quasiprobability distribution to quantify the contribution of coherence to work extraction during generic, cyclic quantum evolutions. In particular, we focus on ``anomalous processes'', counterintuitive scenarios in which, due to the negativity of the quasiprobability distribution, work can be extracted even when individual processes are associated with energy gain. Applying this framework to qubits undergoing sequences of single- and two-qubit gate operations, we identify specific conditions under which such anomalous work exchanges occur. Furthermore, we analyze the quasiprobabilistic structure of deep quantum circuits and establish a compositional relation linking the work statistics of full circuits to those of their constituent gates. Our work highlights the role of coherence in the thermodynamics of quantum computation and provides a foundation for systematically studying potential thermodynamic relevance of specific quantum circuits.

quant-ph↗

arXiv2025

Predicting fermionic densities using a Projected Quantum Kernel method

We use a support vector regressor based on a projected quantum kernel method to predict the density structure of 1D fermionic systems of interest in quantum chemistry and quantum matter. The kernel is built on with the observables of a quantum reservoir implementable with interacting Rydberg atoms. Training and test data of the fermionic system are generated using a Density Functional Theory approach. We test the performance of the method for several Hamiltonian parameters, finding a general common behavior of the error as a function of measurement time. At sufficiently large measurement times, we find that the method outperforms the classical linear kernel method and can be competitive with the radial basis function method.

quant-ph↗

arXiv2024

Extractable energy from quantum superposition of current states

We explore the energy content of superpositions of current states. Specifically, we focus on the maximum energy that can be extracted from them through local unitary transformations. The figure of merit we employ is the local ergotropy. We perform a complete analysis in the whole range of the system's parameters. This way, we prove that superpositions of two current states in spatially closed spin networks are characterized by specific peaks in extractable energy, generally overcoming the ergotropy of each of the two separate current states characterized by a single winding number. The many-body state dynamics entails to ergotropy evolving in a controlled fashion. The implementation we suggest is based on a Rydberg-atom platform. Optimal transformations able to extract locally the maximum possible amount of energy are sorted out.

quant-ph↗

arXiv2024

Quantum superpositions of current states in Rydberg-atom networks

Quantum simulation of many-body quantum systems using Rydberg-atom platforms has become of extreme interest in the last years. The possibility to realize spin Hamiltonians and the accurate control at the single atom level paved the way for the study of quantum phases of matter and dynamics. Here, we propose a quantum optimal control protocol to engineer current states: quantum states characterized by Rydberg excitations propagating in a given spatially closed tweezer networks. Indeed, current states with different winding numbers can be generated on demand. Besides those ones with single winding number, superposition of quantum current states characterized by more winding numbers can be obtained. The single current states are eigenstates of the current operator that therefore can define an observable that remains persistent at any time. In particular, the features of the excitations dynamics reflects the nature of current states, a fact that in principle can be used to characterize the nature of the flow experimentally without the need of accessing high order correlators.

quant-ph↗

arXiv2023

Perspective on new implementations of atomtronic circuits

In this article, we provide perspectives for atomtronics circuits on quantum technology platforms beyond simple bosonic or fermionic cold atom matter-wave currents. Specifically, we consider (i) matter-wave schemes with multi-component quantum fluids; (ii) networks of Rydberg atoms that provide a radically new concept of atomtronics circuits in which the flow, rather than in terms of matter, occurs through excitations; (iii) hybrid matter-wave circuits - cavities systems that can be used to study atomtronic circuits beyond the standard solutions and provide new schemes for integrated matter-wave networks. We also sketch how driving these systems can open new pathways for atomtronics.

cond-mat.quant-gas↗

arXiv2023

Controlled dissipation for Rydberg atom experiments

We demonstrate a simple technique for adding controlled dissipation to Rydberg atom experiments. In our experiments we excite cold rubidium atoms in a magneto-optical trap to $70$-S Rydberg states, whilst simultaneously inducing forced dissipation by resonantly coupling the Rydberg state to a hyperfine level of the short-lived $6$-P state. The resulting effective dissipation can be varied in strength and switched on and off during a single experimental cycle.

physics.atom-ph↗

arXiv2023

Coherent excitation transport through ring-shaped networks

The coherent quantum transport of matter wave through a ring-shaped circuit attached to leads defines an iconic system in mesoscopic physics that has allowed both to explore fundamental questions in quantum science and to draw important avenues for conceiving devices of practical use. Here we study the source-to-drain transport of excitations going through a ring-network, without propagation of matter waves. We model the circuit in terms of a spin system with specific long-range interactions that are relevant for quantum technology, such as Rydberg atoms trapped in optical tweezers or ion traps. Inspired by the logic of rf- and dc-SQUIDs, we consider rings with one and two local energy offsets, or detunings. As a combination of specific phase shifts in going though the localized detunings and as a result of coherent tunneling, we demonstrate how the transport of excitations can be controlled, with a distinctive dependence on the range of interactions.

cond-mat.quant-gas↗

arXiv2022

Controlled flow of excitations in a ring-shaped network of Rydberg atoms

Highly excited Rydberg atoms are a powerful platform for quantum simulation and information processing. Here, we propose atomic ring networks to study chiral currents of Rydberg excitations. The currents are controlled by a phase pattern imprinted via a Raman scheme and can persist even in the presence of dephasing. Depending on the interplay between the Rabi coupling of Rydberg states and the dipole-dipole atom interaction, the current shows markedly different features. The excitations propagate with a velocity displaying a characteristic peak in time, reflecting the chiral nature of the current. We find that the time-averaged current in a quench behaves similarly to the ground-state current. This analysis paves the way for the development of new methods to transport information in atomic networks.

cond-mat.quant-gas↗