arXiv subjects

Mathias B. M. Svendsen

Publications and source records attributed to Mathias B. M. Svendsen.

6 recordsLinked to original sources

arXiv2026

Robust topological quantum state transfer with long-range interactions in Rydberg arrays

We develop a theoretical framework for fast, robust and high-fidelity topological quantum state transfer in one-dimensional systems with long-range couplings, motivated by chains of Rydberg atoms with dipole-dipole interactions. Such long-range interactions naturally give rise to extended Su-Schrieffer-Heeger and Rice-Mele models supporting topologically protected edge states. We show that these edge states enable high-fidelity edge-to-edge excitation transfer using both time-independent protocols, based on coherent edge state dynamics, and time-dependent protocols, based on adiabatic modulation of system parameters. Long-range couplings play a central role by enhancing the relevant energy gaps, leading to a substantial improvement in transfer efficiency compared to nearest neighbour models. The resulting transfer is robust against positional disorder, reflecting its topological origin and highlighting the potential of long-range interacting platforms for reliable quantum state transfer.

quant-ph↗

arXiv2026

Non-equilibrium exciton dynamics in tailored molecular potentials of Rydberg ion crystals

Trapped ions excited to high-lying electronic states combine strongly coupled collective vibrational and electronic degrees of freedom with long-ranged interparticle interactions. These ingredients enable the quantum simulation of biochemical processes, associated with the dynamics of excitons in non-perturbative parameter regimes. The key feature of such a quantum simulator are electronic-state-dependent molecular potential surfaces which can be strongly coupled. This allows to shed light on a variety of mechanisms underlying exciton transport. We illustrate this in a system of three trapped ions, which is amenable to an ab initio treatment. Given that ion traps can be routinely prepared with hundreds of ions, these quantum simulators can immediately realise scenarios which are inaccessible by current numerical methods.

physics.atom-ph↗

arXiv2025

Topological phases in two-dimensional Rydberg lattices

Rydberg lattice gases are at the forefront of quantum simulation platforms due to their inherent strong dipole-dipole interactions, long life-times and high degree of control currently achievable in experiments. We propose a simple and experimentally realizable two-dimensional lattice model consisting of two offset square sublattices of Rydberg atoms for the simulation of a so-called two-dimensional SSH model. This model reveals a plethora of topological phases, all connected through the variation of the lattice geometry. We predict the appearance of edge and corner states characterizing topological insulators, as well as pairs of topologically charged Dirac points associated with tilted and anisotropic cones in gapless semimetallic phases. The position, tilt and degree of anisotropy of the cones, which may determine the transport porperties of the system, are tunable via the sublattice offset parameters.

quant-ph↗

arXiv2024

Topological photon pumping in quantum optical systems

We establish the concept of topological pumping in one-dimensional systems with long-range couplings and apply it to the transport of a photon in quantum optical systems. In our theoretical investigation, we introduce an extended version of the Rice-Mele model with all-to-all couplings. By analyzing its properties, we identify the general conditions for topological pumping and theoretically and numerically demonstrate topologically protected and dispersionless transport of a photon on a one-dimensional emitter chain. As concrete examples, we investigate three different popular quantum optics platforms, namely Ryd\-berg atom lattices, dense lattices of atoms excited to low-lying electronic states, and atoms coupled to waveguides, using experimentally relevant parameters. We observe that despite the long-ranged character of the dipole-dipole interactions, topological pumping facilitates the transport of a photon with a fidelity per cycle which can reach 99.9\%. Moreover, we find that the photon pumping process remains topologically protected against local disorder in the coupling parameters.

quant-ph↗

arXiv2023

Modified dipole-dipole interactions in the presence of a nanophotonic waveguide

When an emitter ensemble interacts with the electromagnetic field, dipole-dipole interactions are induced between the emitters. The magnitude and shape of these interactions are fully determined by the specific form of the electromagnetic field modes. If the emitters are placed in the vicinity of a nanophotonic waveguide, such as a cylindrical nanofiber, the complex functional form of these modes makes the analytical evaluation of the dipole-dipole interaction cumbersome and numerically costly. In this work, we provide a full detailed description of how to successfully calculate these interactions, outlining a method that can be easily extended to other environments and boundary conditions. Such exact evaluation is of importance as, due to the collective character of the interactions and dissipation in this kind of systems, any small modification of the interactions may lead to dramatic changes in experimental observables, particularly as the number of emitters increases. We illustrate this by calculating the transmission signal of the light guided by a cylindrical nanofiber in the presence of a nearby chain of emitters.

quant-ph↗

arXiv2021

Curvature-induced long ranged supercurrents in diffusive SFS Josephson Junctions, with dynamic $0-π$ transition

We report that spin supercurrents can be induced in diffusive SFS Josephson junctions without any magnetic misalignment or intrinsic spin orbit coupling. Instead, the pathway to spin triplet generation is provided via geometric curvature, and results in a long ranged Josephson effect. In addition, the curvature is shown to induce a dynamically tunable $0-π$ transition in the junction. We provide the analytic framework and discuss potential experimental and innovation implications.

cond-mat.supr-con↗