Universität Ulm

Making Quantum Collision Models Exact

Thibaut Lacroix, Dario Cilluffo, Susana F. Huelga +1

Quantum collision describe open quantum systems through repeated interactions with a coarse-grained environment. However, a complete certification of these models is lacking, as no…

Efficiency of optimal control for noisy spin qubits in diamond

Hendry M. Lim, Genko T. Genov, Roberto Sailer +4

Decoherence is a major challenge for quantum technologies. A way to mitigate its negative impact is by employing quantum optimal control. The decoherence dynamics varies significan…

Towards quantum error correction with two-body gates for quantum registers based on nitrogen-vacancy centers in diamond

Daniel Dulog, Martin B. Plenio

Color centers in diamond provide a possible hardware for quantum computation, where the most basic quantum information processing unit are nitrogen-vacancy (NV) centers, each in co…

Asymptotic relaxation in quantum Markovian dynamics

Giovanni Di Meglio, Dariusz Chruściński, Koenraad Audenaert +2

We investigate the long-time behavior of quantum Markovian dynamics generated by time-dependent Gorini-Kossakowski-Lindblad-Sudarshan (GKLS) master equations. We introduce a notion…

quant-ph2024★ 2 cited

Connecting extended Wigner's friend arguments and noncontextuality

Laurens Walleghem, Yìlè Yīng, Rafael Wagner +1

The Local Friendliness argument is an extended Wigner's friend no-go theorem that provides strong constraints on the nature of reality -- stronger even than those imposed by Bell's…

Connectivity matters: Impact of bath modes ordering and geometry in open quantum system simulation with Tensor Network States

Thibaut Lacroix, Brendon W. Lovett, Alex W. Chin

Being able to study the dynamics of quantum systems interacting with several environments is important in many settings ranging from quantum chemistry to quantum thermodynamics, th…

Angular Momentum Entanglement Mediated By General Relativistic Frame Dragging

Trinidad B. Lantaño, Luciano Petruzziello, Susana F. Huelga +1

Current proposals to probe the quantum nature of gravity in the low-energy regime predominantly focus on the Newtonian interaction term. In this work, we present a theoretical expl…

Resource state generation for a multispin register in a hybrid matter-photon quantum information processor

Yu Liu, Martin B. Plenio

Hybrid quantum architectures that integrate matter and photonic degrees of freedom present a promising pathway toward scalable, fault-tolerant quantum computing. This approach need…

Continuity bounds for quantum entropies arising from a fundamental entropic inequality

Koenraad Audenaert, Bjarne Bergh, Nilanjana Datta +3

We establish a tight upper bound for the difference in von Neumann entropies between two quantum states, $ρ_{1}$ and $ρ_{2}$ . This bound is expressed in terms of the von Neumann entrop…

quant-ph2024★ 21 cited

MPSDynamics.jl: Tensor network simulations for finite-temperature (non-Markovian) open quantum system dynamics

Thibaut Lacroix, Brieuc Le Dé, Angela Riva +2

The MPSDynamics.jl package provides an easy to use interface for performing open quantum systems simulations at zero and finite temperatures. The package has been developed with th…

quant-ph2024★ 5 cited

Spectral Density Modulation and Universal Markovian Closure of Fermionic Environments

Davide Ferracin, Andrea Smirne, Susana F. Huelga +2

The combination of chain-mapping and tensor-network techniques provides a powerful tool for the numerically exact simulation of open quantum systems interacting with structured env…

quant-ph2024★ 8 cited

Contextuality in anomalous heat flow

Naim Elias Comar, Danilo Cius, Luis Felipe Santos +2

In classical thermodynamics, heat must spontaneously flow from hot to cold systems. In quantum thermodynamics, the same law applies when considering multipartite product thermal st…

quant-ph2024★ 3 cited

Decoupling of External and Internal Dynamics in Driven Two-level Systems

Samuel Böhringer, Alexander Friedrich

We show how a laser driven two-level system including quantized external degrees of freedom for each state can be decoupled into a set of oscillator equations acting only on the ex…

quant-ph2024★ 7 cited

Optically Hyperpolarized Materials for Levitated Optomechanics

Marit O. E. Steiner, Julen S. Pedernales, Martin B. Plenio

We explore the potential of levitating solids embedded with non-permanent, optically controllable electron spins, which can be used to hyperpolarize their nuclear spin environment…

quant-ph2024★ 3 cited

Pulse sequence design for high field NMR with NV centers in dipolarly coupled samples

Carlos Munuera-Javaloy, Ander Tobalina, Jorge Casanova

Diamond-based quantum sensors have enabled high-resolution NMR spectroscopy at the microscale in scenarios where fast molecular motion averages out dipolar interactions among targe…

Robust external spin hyperpolarization of quadrupolar nuclei enabled by strain

Lu Chen, Jiawen Jiang, Martin B. Plenio +1

In a theoretical study, we investigate the spin dynamics of interacting nitrogen-vacancy (NV) centers and quadrupolar I = 3/2 nuclear spins, specifically 11B spins in hexagonal bor…

Certifying nonstabilizerness in quantum processors

Rafael Wagner, Filipa C. R. Peres, Emmanuel Zambrini Cruzeiro +1

Nonstabilizerness, also known as magic, is a crucial resource for quantum computation. The growth in complexity of quantum processing units (QPUs) demands robust and scalable techn…

A hybrid source of quantum light for generation of frequency tunable Fock states

Aleksa Krstić, Priyanshu Tiwari, Florian Höhe +4

We propose a scheme for quantum-light generation in a nonlinear cavity hybridized with a 2-level system and theoretically show that, when excited by a series of controlled pump pul…

quant-ph2024★ 14 cited

$^{13}$ C Hyperpolarization with Nitrogen-Vacancy Centers in Micro- and Nanodiamonds for Sensitive Magnetic Resonance Applications

Rémi Blinder, Yuliya Mindarava, Martin Korzeczek +9

Nuclear hyperpolarization is a known method to enhance the signal in nuclear magnetic resonance (NMR) by orders of magnitude. The present work addresses the $^{13}$ C hyperpolarizat…

quant-ph2024★ 9 cited

Spectral continuum in the Rabi-Stark model

Daniel Braak, Lei Cong, Hans-Peter Eckle +2

The Rabi-Stark model is a non-linear generalization of the quantum Rabi model including the dynamical Stark shift as a tunable term, which can be realized via quantum simulation on…

Multimode-cavity picture of non-Markovian waveguide QED

Dario Cilluffo, Luca Ferialdi, G. Massimo Palma +2

We introduce a picture to describe and intrepret waveguide-QED problems in the non-Markovian regime of long photonic retardation times resulting in delayed coherent feedback. The f…