Condensed Matter Physics, Atomic and Molecular Physics, and Optics
15
Scopus Publications
305
Scholar Citations
9
Scholar h-index
8
Scholar i10-index
Scopus Publications
Digitized counterdiabatic quantum critical dynamics Anne-Maria Visuri, Alejandro Gomez Cadavid, Balaganchi A. Bhargava, Sebastián V. Romero, András Grabarits, Pranav Chandarana, Enrique Solano, Adolfo del Campo, Narendra N. Hegade Npj Quantum Information, 2026 We experimentally demonstrate that a digitized counterdiabatic quantum protocol reduces the number of topological defects created during a fast quench across a quantum phase transition. To show this, we perform quantum simulations of one- and two-dimensional transverse-field Ising models driven from the paramagnetic to the ferromagnetic phase. We utilize superconducting cloud-based quantum processors with up to 156 qubits. Our data reveal that the digitized counterdiabatic protocol reduces defect formation by up to 48% in the fast-quench regime–an improvement hard to achieve through digitized quantum annealing under current noise levels. The experimental results closely match theoretical and numerical predictions at short evolution times before deviating at longer times due to hardware noise. In one dimension, we derive an analytic solution for the defect number distribution in the fast-quench limit. For two-dimensional geometries, where analytical solutions are unknown and numerical simulations are challenging, we use advanced matrix product state methods. Our findings indicate a practical way to control topological defect formation during fast quenches and highlight the utility of counterdiabatic protocols for quantum optimization and quantum simulation in material design on current quantum processors.
Bias-field digitized counterdiabatic quantum algorithm for higher-order binary optimization Sebastián V. Romero, Anne-Maria Visuri, Alejandro Gomez Cadavid, Anton Simen, Enrique Solano, Narendra N. Hegade Communications Physics, 2025 Combinatorial optimization plays a crucial role in many industrial applications. While classical computing often struggles with complex instances, quantum optimization emerges as a promising alternative. Here, we present an enhanced bias-field digitized counterdiabatic quantum optimization (BF-DCQO) algorithm to address higher-order unconstrained binary optimization (HUBO). We apply BF-DCQO to a HUBO problem featuring three-local terms in the Ising spin-glass model, validated experimentally using 156 qubits on an IBM quantum processor. In the studied instances, our results outperform standard methods such as the quantum approximate optimization algorithm, quantum annealing, simulated annealing, and Tabu search. Furthermore, we provide numerical evidence of the feasibility of a similar HUBO problem on a 433-qubit Osprey-like quantum processor. Finally, we solve denser instances of the MAX 3-SAT problem in an IonQ emulator. Our results show that BF-DCQO offers an effective path for solving large-scale HUBO problems on current and near-term quantum processors.
Digital-analog quantum computing of fermion-boson models in superconducting circuits Shubham Kumar, Narendra N. Hegade, Anne-Maria Visuri, Balaganchi A. Bhargava, Juan F. R. Hernandez, E. Solano, F. Albarrán-Arriagada, G. Alvarado Barrios Npj Quantum Information, 2025 High-fidelity quantum simulations demand hardware-software co-design architectures, which are crucial for adapting to complex problems such as strongly correlated dynamics in condensed matter. By leveraging co-design strategies, we can enhance the performance of state-of-the-art quantum devices in the noisy intermediate quantum (NISQ) and early error-correction regimes. In this direction, we propose a digital-analog quantum algorithm for simulating the Hubbard–Holstein model, describing strongly correlated fermion-boson interactions, in a suitable architecture with superconducting circuits. It comprises a linear chain of qubits connected by resonators, emulating electron–electron (e–e) and electron–phonon (e–p) interactions, as well as fermion tunneling. Our approach is adequate for digital-analog quantum computing (DAQC) of fermion-boson models, including those described by the Hubbard–Holstein model. We show the reduction in the circuit depth of the DAQC algorithm, a sequence of digital steps and analog blocks, outperforming the purely digital approach. We exemplify the quantum simulation of a half-filled two-site Hubbard–Holstein model. In this example, we obtain time-dependent state fidelities larger than 0.98, showing that our proposal is suitable for studying the dynamical behavior of solid-state systems. Our proposal opens the door to computing complex systems for chemistry, materials, and high-energy physics.
Sine-Gordon dynamics in spin transport A.-M. Visuri Physical Review A, 2024 We study spin transport in a one-dimensional finite-length wire connected to fermionic leads. The interacting wire is described by the sine-Gordon model while the leads are either noninteracting or interacting Luttinger liquids. We calculate the spin current driven by a spin bias by solving numerically the classical equation of motion, and find that the cosine term in the sine-Gordon model gives rise to an oscillating spin current when the spin bias exceeds its critical value. We discuss the results in connection with transport experiments with ultracold atoms.
DC transport in a dissipative superconducting quantum point contact Anne-Maria Visuri, Jeffrey Mohan, Shun Uchino, Meng-Zi Huang, Tilman Esslinger, Thierry Giamarchi Physical Review Research, 2023 We study the current-voltage characteristics of a superconducting junction with particle losses at the contacts. We adopt the Keldysh formalism to compute the steady-state current for varying transmission of the contact. In the low transmission regime, the dissipation leads to an enhancement of the current at low bias, a nonmonotonic dependence of current on dissipation, and the emergence of new structures in the current-voltage curves. The effect of dissipation by particle loss is found to be qualitatively different from that of a finite temperature and a finite inelastic scattering rate in the reservoirs.
Superfluid Signatures in a Dissipative Quantum Point Contact Meng-Zi Huang, Jeffrey Mohan, Anne-Maria Visuri, Philipp Fabritius, Mohsen Talebi, Simon Wili, Shun Uchino, Thierry Giamarchi, Tilman Esslinger Physical Review Letters, 2023 We measure superfluid transport of strongly interacting fermionic lithium atoms through a quantum point contact with local, spin-dependent particle loss. We observe that the characteristic non-Ohmic superfluid transport enabled by high-order multiple Andreev reflections transitions into an excess Ohmic current as the dissipation strength exceeds the superfluid gap. We develop a model with mean-field reservoirs connected via tunneling to a dissipative site. Our calculations in the Keldysh formalism reproduce the observed nonequilibrium particle current, yet do not fully explain the observed loss rate or spin current.
Nonlinear transport in the presence of a local dissipation A.-M. Visuri, T. Giamarchi, C. Kollath Physical Review Research, 2023 We characterize the particle transport, particle loss, and nonequilibrium steady states in a dissipative one-dimensional lattice connected to reservoirs at both ends. The free-fermion reservoirs are fixed at different chemical potentials, giving rise to particle transport. The dissipation is due to a local particle loss acting on the center site. We compute the conserved current and loss current as functions of voltage in the nonlinear regime using a Keldysh description. The currents show step-like features which are affected differently by the local loss: The steps are either smoothened, nearly unaffected, or even enhanced, depending on the spatial symmetry of the single-particle eigenstate giving rise to the step. Additionally, we compute the particle density and momentum distributions in the chain. At a finite voltage, two Fermi momenta can occur, connected to different wavelengths of Friedel oscillations on either side of the lossy site. We find that the wavelengths are determined by the chemical potentials in the reservoirs rather than the average density in the lattice.
Symmetry-Protected Transport through a Lattice with a Local Particle Loss A.-M. Visuri, T. Giamarchi, C. Kollath Physical Review Letters, 2022 We study particle transport through a chain of coupled sites connected to free-fermion reservoirs at both ends, subjected to a local particle loss. The transport is characterized by calculating the conductance and particle density in the steady state using the Keldysh formalism for open quantum systems. In addition to a reduction of conductance, we find that transport can remain (almost) unaffected by the loss for certain values of the chemical potential in the lattice. We show that this "protected" transport results from the spatial symmetry of single-particle eigenstates. At a finite voltage, the density profile develops a drop at the lossy site, connected to the onset of nonballistic transport.
Spin transport in a one-dimensional quantum wire A.-M. Visuri, M. Lebrat, S. Häusler, L. Corman, T. Giamarchi Physical Review Research, 2020 We analyze the spin transport through a finite-size one-dimensional interacting wire connected to noninteracting leads. By combining renormalization-group arguments with other analytic considerations such as the memory function technique and instanton tunneling, we find the temperature dependence of the spin conductance in different parameter regimes in terms of interactions and the wire length. The temperature dependence is found to be nonmonotonic. In particular, the system approaches perfect spin conductance at zero temperature for both attractive and repulsive interactions, in contrast with the static spin conductivity. We discuss the connection of our results to recent experiments with ultracold atoms and compare the theoretical prediction to experimental data in the parameter regime where temperature is the largest energy scale.
Impurity coupled to a lattice with disorder A.-M. Visuri, C. Berthod, T. Giamarchi Physical Review A, 2018 We study the time-dependent occupation of an impurity state hybridized with a continuum of extended or localized states. Of particular interest is the return probability, which gives the long-time limit of the average impurity occupation. In the extended case, the return probability is zero unless there are bound states of the impurity and continuum. We present exact expressions for the return probability of an impurity state coupled to a lattice, and show that the existence of bound states depends on the dimension of the lattice. In a disordered lattice with localized eigenstates, the finite extent of the eigenstates results in a nonzero return probability. We investigate different parameter regimes numerically by exact diagonalization, and show that the return probability can serve as a measure of the localization length in the regime of weak hybridization and disorder. Possible experimental realizations with ultracold atoms are discussed.
Digitized counterdiabatic quantum critical dynamics AM Visuri, A Gomez Cadavid, BA Bhargava, SV Romero, A Grabarits, ... npj Quantum Information , 2026 2026 Citations: 7
Constant depth digital-analog counterdiabatic quantum computing BA Bhargava, S Kumar, AM Visuri, PA Erdman, E Solano, NN Hegade arXiv preprint arXiv:2601.01154 , 2026 2026 Citations: 2
Digitized Counterdiabatic Quantum Sampling NN Hegade, NL Kortikar, BA Bhargava, JFR Hernández, AG Cadavid, ... arXiv preprint arXiv:2510.26735 , 2025 2025 Citations: 2
Bias-field digitized counterdiabatic quantum algorithm for higher-order binary optimization SV Romero, AM Visuri, AG Cadavid, A Simen, E Solano, NN Hegade Communications Physics 8 (1), 348 , 2025 2025 Citations: 42
Digital-analog quantum computing of fermion-boson models in superconducting circuits S Kumar, NN Hegade, AM Visuri, BA Bhargava, JFR Hernandez, ... npj Quantum Information 11 (1), 43 , 2025 2025 Citations: 16
Digital-analog quantum computing of fermion-boson models in superconducting circuits, npj Quantum Inf S Kumar, NN Hegade, AM Visuri, BA Bhargava, JFR Hernandez, ... 2025 Citations: 5
Sine-Gordon dynamics in spin transport AM Visuri Physical Review A 109 (5), 053310 , 2024 2024 Citations: 2
DC transport in a dissipative superconducting quantum point contact AM Visuri, J Mohan, S Uchino, MZ Huang, T Esslinger, T Giamarchi Physical Review Research 5 (3), 033095 , 2023 2023 Citations: 18
Superfluid signatures in a dissipative quantum point contact MZ Huang, J Mohan, AM Visuri, P Fabritius, M Talebi, S Wili, S Uchino, ... Physical Review Letters 130 (20), 200404 , 2023 2023 Citations: 45
Nonlinear transport in the presence of a local dissipation AM Visuri, T Giamarchi, C Kollath Physical Review Research 5 (1), 013195 , 2023 2023 Citations: 33
Symmetry-protected transport through a lattice with a local particle loss AM Visuri, T Giamarchi, C Kollath Physical Review Letters 129 (5), 056802 , 2022 2022 Citations: 38
Controlling and probing superfluid transport through an atomic quantum point contact P Fabritius, J Mohan, AM Visuri, S Häusler, M Talebi, S Wili, T Giamarchi, ... APS March Meeting Abstracts 2022, G00. 309 , 2022 2022
Transport through a dissipative superfluid contact AM Visuri APS March Meeting Abstracts 2022, F50. 012 , 2022 2022
Observation of superfluid current through a dissipative quantum point contact J Mohan, P Fabritius, AM Visuri, M Talebi, S Wili, S Uchino, T Giamarchi, ... APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts 2022 … , 2022 2022
Spin transport in a one-dimensional quantum wire AM Visuri, M Lebrat, S Häusler, L Corman, T Giamarchi Physical Review Research 2 (2), 023062 , 2020 2020 Citations: 18
Spin drag in a one-dimensional quantum wire AM Visuri, T Giamarchi APS March Meeting Abstracts 2019, C24. 008 , 2019 2019
Impurity coupled to a lattice with disorder AM Visuri, C Berthod, T Giamarchi Physical Review A 98 (5), 053607 , 2018 2018 Citations: 5
Impurity and soliton dynamics in a Fermi gas with nearest-neighbor interactions AM Visuri, P Törmä, T Giamarchi Physical Review A 95 (6), 063605 , 2017 2017 Citations: 3
Impurity dynamics and nearest-neighbor interactions in one-dimensional lattices AM Visuri Aalto University , 2017 2017
Decoherence of an impurity in a one-dimensional fermionic bath with mass imbalance AM Visuri, JJ Kinnunen, JE Baarsma, P Törmä Physical Review A 94 (1), 013619 , 2016 2016 Citations: 7
MOST CITED SCHOLAR PUBLICATIONS
Superfluid signatures in a dissipative quantum point contact MZ Huang, J Mohan, AM Visuri, P Fabritius, M Talebi, S Wili, S Uchino, ... Physical Review Letters 130 (20), 200404 , 2023 2023.0 Citations: 45
Bias-field digitized counterdiabatic quantum algorithm for higher-order binary optimization SV Romero, AM Visuri, AG Cadavid, A Simen, E Solano, NN Hegade Communications Physics 8 (1), 348 , 2025 2025.0 Citations: 42
Two-dimensional time-dependent numerical modeling of edge effects in dye solar cells K Miettunen, J Halme, AM Visuri, P Lund The Journal of Physical Chemistry C 115 (14), 7019-7031 , 2011 2011.0 Citations: 41
Symmetry-protected transport through a lattice with a local particle loss AM Visuri, T Giamarchi, C Kollath Physical Review Letters 129 (5), 056802 , 2022 2022.0 Citations: 38
Nonlinear transport in the presence of a local dissipation AM Visuri, T Giamarchi, C Kollath Physical Review Research 5 (1), 013195 , 2023 2023.0 Citations: 33
DC transport in a dissipative superconducting quantum point contact AM Visuri, J Mohan, S Uchino, MZ Huang, T Esslinger, T Giamarchi Physical Review Research 5 (3), 033095 , 2023 2023.0 Citations: 18
Spin transport in a one-dimensional quantum wire AM Visuri, M Lebrat, S Häusler, L Corman, T Giamarchi Physical Review Research 2 (2), 023062 , 2020 2020.0 Citations: 18
Digital-analog quantum computing of fermion-boson models in superconducting circuits S Kumar, NN Hegade, AM Visuri, BA Bhargava, JFR Hernandez, ... npj Quantum Information 11 (1), 43 , 2025 2025.0 Citations: 16
Digitized counterdiabatic quantum critical dynamics (2025) AM Visuri, AG Cadavid, BA Bhargava, SV Romero, A Grabarits, ... arXiv preprint arXiv:2502.15100 , 0 Citations: 9
Excitations and impurity dynamics in a fermionic Mott insulator with nearest-neighbor interactions AM Visuri, T Giamarchi, P Törmä Physical Review B 93 (12), 125110 , 2016 2016.0 Citations: 8
Digitized counterdiabatic quantum critical dynamics AM Visuri, A Gomez Cadavid, BA Bhargava, SV Romero, A Grabarits, ... npj Quantum Information , 2026 2026.0 Citations: 7
Decoherence of an impurity in a one-dimensional fermionic bath with mass imbalance AM Visuri, JJ Kinnunen, JE Baarsma, P Törmä Physical Review A 94 (1), 013619 , 2016 2016.0 Citations: 7
Digital-analog quantum computing of fermion-boson models in superconducting circuits, npj Quantum Inf S Kumar, NN Hegade, AM Visuri, BA Bhargava, JFR Hernandez, ... 2025.0 Citations: 5
Impurity coupled to a lattice with disorder AM Visuri, C Berthod, T Giamarchi Physical Review A 98 (5), 053607 , 2018 2018.0 Citations: 5
Moving perturbation in a one-dimensional Fermi gas AM Visuri, DH Kim, JJ Kinnunen, F Massel, P Törmä Physical Review A 90 (5), 051603 , 2014 2014.0 Citations: 4
Impurity and soliton dynamics in a Fermi gas with nearest-neighbor interactions AM Visuri, P Törmä, T Giamarchi Physical Review A 95 (6), 063605 , 2017 2017.0 Citations: 3
Constant depth digital-analog counterdiabatic quantum computing BA Bhargava, S Kumar, AM Visuri, PA Erdman, E Solano, NN Hegade arXiv preprint arXiv:2601.01154 , 2026 2026.0 Citations: 2
Digitized Counterdiabatic Quantum Sampling NN Hegade, NL Kortikar, BA Bhargava, JFR Hernández, AG Cadavid, ... arXiv preprint arXiv:2510.26735 , 2025 2025.0 Citations: 2
Sine-Gordon dynamics in spin transport AM Visuri Physical Review A 109 (5), 053310 , 2024 2024.0 Citations: 2
Controlling and probing superfluid transport through an atomic quantum point contact P Fabritius, J Mohan, AM Visuri, S Häusler, M Talebi, S Wili, T Giamarchi, ... APS March Meeting Abstracts 2022, G00. 309 , 2022 2022.0
