A5005947855- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Frequency and Time Standards
- Atomic and Subatomic Physics Research
- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Quantum Mechanics and Applications
- Quantum and electron transport phenomena
- Advanced Materials Characterization Techniques
- Advanced Data Storage Technologies
- Advanced Thermodynamics and Statistical Mechanics
- Scientific Measurement and Uncertainty Evaluation
- Radioactive Decay and Measurement Techniques
- Distributed and Parallel Computing Systems
- Parallel Computing and Optimization Techniques
- Neural Networks and Reservoir Computing
- Advancements in Semiconductor Devices and Circuit Design
- Quantum, superfluid, helium dynamics
- Low-power high-performance VLSI design
- Neural Networks and Applications
- Cold Fusion and Nuclear Reactions
- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Atmospheric Ozone and Climate
- Computability, Logic, AI Algorithms
- Spectroscopy and Quantum Chemical Studies
Fraunhofer Institute for Integrated Circuits
2022-2025
Fraunhofer Center for Applied Research on Supply Chain Services
2024
Center for Integrated Quantum Science and Technology
2017-2023
Universität Ulm
2017-2023
Circuit cutting, the partitioning of quantum circuits into smaller independent fragments, has become a promising avenue for scaling up current quantum-computing experiments. Here, we introduce scheme joint cutting two-qubit rotation gates based on virtual gate-teleportation protocol. With that, significantly lower previous upper bounds sampling overhead and prove optimality scheme. Furthermore, show that no classical communication between circuit partitions is required. For parallel derive...
In a quantum version of the twin paradox, atom interferometers generate one clock, aging at different rates simultaneously.
Metric descriptions of gravitation, among them general relativity as today's established theory, are founded on assumptions summarized by the Einstein equivalence principle (EEP). Its violation would hint at unknown physics and could be a leverage for development quantum gravity. Atomic clocks excellent systems to probe aspects EEP connected (proper) time have evolved into working horse tests local position invariance (LPI). Even though operational definition requires localized idealized...
Atomic interference experiments can probe the gravitational redshift via internal energy splitting of atoms and thus give direct access to test universality coupling between matter-energy gravity at different spacetime points. By including possible violations equivalence principle in a fully quantized treatment all degrees freedom, we characterize how sensitivity arises atomic clocks atom interferometers, as well their underlying limitations. Specifically, show that: (i.) Contributions...
Quantum reinforcement learning is an emerging field at the intersection of quantum computing and machine learning. While we intend to provide a broad overview literature on - our interpretation this term will be clarified below put particular emphasis recent developments. With focus already available noisy intermediate-scale devices, these include variational circuits acting as function approximators in otherwise classical setting. In addition, survey algorithms based future fault-tolerant...
Benchmarking and establishing proper statistical validation metrics for reinforcement learning (RL) remain ongoing challenges, where no consensus has been established yet. The emergence of quantum computing its potential applications in (QRL) further complicate benchmarking efforts. To enable valid performance comparisons to streamline current research this area, we propose a novel methodology, which is based on estimator sample complexity definition outperformance. Furthermore, considering...
Despite the continuous advancements in size and robustness of real quantum devices, reliable large-scale computers are not yet available. Hence, classical simulation algorithms remains crucial for testing new methods estimating advantage. Pushing to their limit is essential, particularly due inherent exponential complexity. Besides established Schr\"odinger-style full statevector simulation, so-called Hybrid Schr\"odinger-Feynman (HSF) approaches have shown promise make simulations more...
Dark matter or violations of the Einstein equivalence principle influence motion atoms, their internal states as well electromagnetic fields, thus causing a signature in signal atomic detectors. To model such new physics, we introduce dilaton fields and study modified propagation light used to manipulate atoms light-pulse atom interferometers. Their interference is dominated by matter's coupling gravity dilaton. Even though field contributes phase, no additional dilaton-dependent effect can...
Circuit cutting, the decomposition of a quantum circuit into independent partitions, has become promising avenue towards experiments with larger circuits in noisy-intermediate scale (NISQ) era. While previous work focused on cutting qubit wires or two-qubit gates, this we introduce method for multi-controlled Z gates. We construct and prove upper bound <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mi class="MJX-tex-caligraphic"...
Light-pulse atom interferometers constitute powerful quantum sensors for inertial forces. They are based on delocalised spatial superpositions and the combination with internal transitions directly links them to atomic clocks. Since classical tests of gravitational redshift a comparison two clocks localised at different positions under gravity, it is promising explore whether aforementioned competitive alternative general relativity. Here we present specific geometry which together state...
Light-pulse atom interferometers are powerful quantum sensors, however, their accuracy for example in tests of the weak equivalence principle is limited by various spurious influences like magnetic stray fields or blackbody radiation. Pushing therefore requires a detailed assessment size such deleterious effects. Here, we present systematic operator expansion to obtain phase shifts and contrast analytically powers perturbation. The result can either be employed robust straightforward...
Variational quantum algorithms (VQAs) have attracted a lot of attention from the computing community for last few years. Their hybrid quantum-classical nature with relatively shallow circuits makes them promising platform demonstrating capabilities noisy intermediate scale (NISQ) devices. Although classical machine learning focuses on gradient-based parameter optimization, finding near-exact gradients variational (VQCs) parameter-shift rule introduces large sampling overhead. Therefore,...
Quantum computing is a promising technology to address combinatorial optimization problems, for example via the quantum approximate algorithm (QAOA). Its potential, however, hinges on scaling toy problems sizes relevant industry. In this study, we challenge by an elaborate combination of two decomposition methods, namely graph shrinking and circuit cutting. Graph reduces problem size before encoding into QAOA circuits, while cutting decomposes circuits fragments execution medium-scale...
We report on the design, construction, and characterization of a 10 m-long high-performance magnetic shield for Very Long Baseline Atom Interferometry (VLBAI). achieve residual fields below 4 nT longitudinal inhomogeneities 2.5 nT/m over 8 m along direction. Our modular design can be extended to longer baselines without compromising shielding performance. Such setup constrains biases associated with field gradients sub-pm/$\textrm{s}^2$ level in atomic matterwave accelerometry rubidium atoms...
We present analytical studies of a boson-fermion mixture at zero temperature with spin-polarized fermions. Using the Thomas-Fermi approximation for bosons and local-density fermions, we find large variety different density shapes. In case continuous density, obtain analytic conditions each configuration attractive as well repulsive interaction. Furthermore, analytically show that all scenarios describe are minima grand-canonical energy functional. Finally, provide full classification...
A major challenge in high-precision light-pulse atom interferometric experiments such as tests of the weak equivalence principle is uncontrollable dependency phase on initial velocity and position atoms presence inhomogeneous gravitational fields. To overcome this limitation, mitigation strategies have been proposed, however, valid only for harmonic potentials or small branch separations more general situations. Here we provide a formula anharmonic perturbation including local effects that...
With the increasing sophistication and capability of quantum hardware, its integration, employment in high performance computing (HPC) infrastructure becomes relevant. This opens largely unexplored access models scheduling questions such quantum-classical environments, going beyond current cloud model. SCIM MILQ is a scheduler for tasks HPC infrastructure. It combines well-established techniques with methods unique to computing, as circuit cutting. can schedule while minimizing makespan,...
Quantum computer simulation software is an integral tool for the research efforts in quantum computing community. An important aspect efficiency of respective frameworks, especially training variational algorithms. Focusing on widely used Qiskit environment, we develop qiskit-torch-module. It improves runtime performance by two orders magnitude over comparable libraries, while facilitating low-overhead integration with existing codebases. Moreover, framework provides advanced tools...
Reinforcement learning is a powerful framework aiming to determine optimal behavior in highly complex decision-making scenarios. This objective can be achieved using policy iteration, which requires solve typically large linear system of equations. We propose the variational quantum iteration (VarQPI) algorithm, realizing this step with NISQ-compatible quantum-enhanced subroutine. Its scalability supported by an analysis structure generic reinforcement environments, laying foundation for...
This paper presents a deep reinforcement learning approach for synthesizing unitaries into quantum circuits. Unitary synthesis aims to identify circuit that represents given unitary while minimizing depth, total gate count, specific or combination of these factors. While past research has focused predominantly on continuous sets, from the parameter-free Clifford+T set remains challenge. Although time complexity this task will inevitably remain exponential in number qubits general unitaries,...
Recently, we introduced [C. Ufrecht and E. Giese, Phys. Rev. A 101, 053615 (2020)] a technique to calculate the phase of light-pulse atom interferometers caused by presence perturbation potentials underlined its power an illustrative example. In preceding Comment [B. Dubetsky, 102, 027301 (2020)], it was pointed out that other, less idealized situations could have been calculated as well. Our Reply emphasizes our method is correct, results from example can be trivially generalized other...