World of QUANTUM | MQV + IBM – Quantum Technologies: from Research to Applications

Abstract
Quantum computers have the potential to solve complex problems efficiently. However, to unleash their full capability, complex quantum systems have to be manufactured, manipulated and measured with unprecedented accuracy and precision. Despite the demanding requirements both at the hardware and the software level, enormous progress has been made in scaling up quantum processors, leading to impressive demonstrations of their future power already today. This presentation provides an overview of leading approaches in scalable quantum computing, highlighting the current status as well as advantages and potential challenges associated with platforms based on atoms and on solid-state systems. Particular attention will be paid to recent developments in the Munich Quantum Valley ecosystem.

Abstract
In the past, the preparation and selective observation of well-defined states of solid-state quantum systems often relied on their interaction with light. However, light has a series of disadvantages, including large foci and typically weak light-matter coupling. In recent years, we demonstrated the coherent coupling of free-electron states to localized light states utilizing the unique capabilities of ultrafast transmission electron microscopy and allowing for a coherence transfer between light and electrons. In this approach, the involved light and plasmonic fields were excited deeply in the classical regime, so that only quantum coherent dynamics of the free electron states were observed, and quantum aspects of the solid-state nanostructure were not essential for the physics involved.
In the MQV Lighthouse project “Free-electron states as ultrafast probes for qubit dynamics in solid-state platforms”, we want to extend this line of research to the interaction of electrons with nanoscale solid-state quantum systems, including localized exciton states in transition metal dichalcogenides and quantum dots. A crucial element in an efficient coupling will involve a tailoring of the photonic environment by TEM-compatible resonator structures which allow for a local enhancement of the electron evanescent field at the position of the quantum system.

Abstract
The NeQuS project aims to establish quantum networks, in which nodes that are located in different research institutes can be linked together by optical photons. The nodes will be based on different hardware, including all major platforms investigated in quantum technology: Superconducting circuits, trapped atoms, nanomechanical resonators, and spins in solids. The long-term vision is to pave the way to a global network of quantum computers, in which distributed quantum tasks including computing, communicating and sensing, can be performed in an efficient, fault-tolerant and provably-secure way.

Abstract
Our project aims at implementing two types of solid-state qubits - semiconductor spin qubits and superconducting flux qubits - as well as superconducting readout components. These quantum processor components will all be realized within the same materials platform: germanium- and silicon-germanium-based semiconductor chips. I will give insights into the fundamental physics underlying this vision of a semiconductor industry compatible platform which allows to combine two types of qubits and their respective advantages on a chip.

Abstract
Quantum sensing combines a wide range of technologies to measure physical quantities such as magnetic and electric fields, distances, velocities, forces, and accelerations with a precision that exceeds that of classical detection methods. The most mature system used for quantum sensing is NV spin centers in diamond, with the advantage that they offer outstanding spin coherence properties at room temperature in a chemically and biologically inert host material. We will present novel material systems with spin defects for quantum sensors that can also operate at room temperature but are positionable closer to the object of study. The goal is to develop high-performance sensors (based on ensembles or single spins) for various applications, fast imaging and spectroscopy technologies with super-resolution capabilities for real-time investigation of chemical reactions, and the investigation of solid-state phenomena.

Abstract
The interdisciplinary research project address the challenge of controlling individual quantum objects without disturbing the fragile quantum-mechanical coherence. The aim is to develop ultrafast photodetectors and sources of single entangled photons as well as to investigate quantum control involving machine learning.

Abstract
There are two central processes in quantum systems: the unitary time evolution and projective measurements that break unitarity. Quantum systems, which are continuously "monitored", e.g., by mid-circuit measurements, are subject to new dynamics called measurement induced quantum walks (MIQW), which correspond to random walks through the Hilbert space. The competition between unitary evolution and projective measurements leads to a surprisingly rich diversity of novel phenomena of monitored quantum systems, like dynamical phase transitions or topological invariants of the quantum evolution. Network modelling plays an important role in understanding and analyzing data structures. We utilize MIQW for a network analysis that quantifies the importance of each network node and of the community structure, which is key in characterizing, e.g., social networks. To compute the centrality and community structure, MIQW are experimentally implemented on transmon quantum computers. We discuss noise models, error prevention and error mitigation schemes. Our results reflect the large potential of new capabilities provided by current quantum computers in terms of mid-circuit measurements.

Abstract
Quantum computers promise a qualitative acceleration of hard computational tasks that are so fundamental that they promise a wide range of industrial applications. The realization of this computational advantage is the subject of current research and depends on the application - and the outcome is often open. We illustrate this in the application of quantum computing to modeling in mechanical engineering as well as in the characterization of the quantum advantage in optimization problems.

Abstract
I present the CQTA with its broad portfolio of applications for quantum computing, ranging from Quantum Field Theory over machine learning and classical optimiziation problems.

Abstract
As Quantum Computing systems mature and make their way out of laboratories into production computing environments, we also must rethink the needed software environments. For one, we must transition from supporting individual physics researchers who are experts in quantum science to a wide range of user communities in the various science disciplines wanting to use the power of quantum computing; at the same time we also must ensure a proper integration into workflows, schedulers, and system software environments used in existing compute environments without which a quantum system will not be practically usable. This talk will highlight the issues associated with this transition and will introduce the Munich Quantum Software Stack, developed as part of the Munich Quantum Valley (MQV) initiative, with which we tackle these challenges for the upcoming quantum systems hosted at LRZ.

Abstract
QuKomIn will establish a Bavarian wide test bed and application centres for research on quantum communication and quantum cryptography. The test bed will connect Metropolitan areas and establish links to neighbouring initiatives inside Germany. The application centres will enable research on free space / satellite-based and fiber-based quantum communication under realistic conditions.

Abstract
We see an impressive development of quantum computers in terms of number of qubits, coherence times and gate fidelities. While, error correction at scale will remain out of reach for the coming years, error mitigation provides a continuous path towards quantum advantage by leveraging noisy devices. In this talk, we discuss recent developments and demonstrations of error mitigation on real quantum devices and next steps towards a near-term quantum advantage for applications.

Abstract
Practical Utility of quantum computing hardware in real-world industrial applications very much depends on the combination of use case, used algorithm, mathematical formulation of the problem and hardware parameters. In this project, industry and research partners with a range of expertise are are developing and implementing a universal frame work which allows a quantitative comparison of various solution strategies using quantum computing in industry.

Abstract
The interplay of quantum fluctuations and interactions can yield to novel quantum phases of matter with fascinating properties. Understanding the physics of such systems is a very challenging problem as it requires to solve quantum many body problems—which are generically exponentially hard on classical computers. In this context, universal quantum computers are potentially an ideal setting for simulating the emergent quantum many-body physics. Here we discuss one concrete application: We use quantum convolutional neural networks (QCNNs) as classifiers and introduce an efficient framework to train these networks.

Abstract
The combined quantum electron-nuclear dynamics is often associated with the Born-Huang expansion of the molecular wave function and the appearance of nonadiabatic effects as a perturbation. On the other hand, native multicomponent representations of electrons and nuclei also exist, which do not rely on any a priori approximation. However, their implementation is hampered by prohibitive scaling costs and therefore quantum computers offer a unique opportunity for extending their use to larger systems. Here, we propose a quantum algorithm for the simulation of the time-evolution of molecular systems in the second quantization framework, which is applied to the simulation of the proton transfer dynamics in malonaldehyde. After partitioning the dynamics into slow and fast components, we show how the entanglement between the electronic and nuclear degrees of freedom can persist over long times if electrons are not adiabatically following the nuclear displacement.

Abstract
Quantum computing as emerging technology is considered promising to provide more efficient or faster solutions to combinatorial optimization challenges. Such tasks appear in many different industrial settings, as e.g. in the logistics sector.
However, in practice it turns out that a straight forward application of quantum algorithms to combinatorial optimization problems does not necessarily lead to a fast solution of good quality. Instead, the use of hybrid algorithms combining classical and quantum computing parts, or possibly quantum-inspired solutions, lead to more promising results.
Taking concrete industrial application scenarios, this talk will discuss how potential quantum-assisted solutions for combinatorial optimization problems work, which challenges exist and which open points remain to be addressed in the future.