Welcome

• Dorota Maria Grabowska (CERN)

Room: Zoom Only

Quantum Sensing for Dark Matter and Gravitational Waves

• Peter Graham

Room: Zoom Only

Quantum Sensors for Particle Physics

• Sunil Golwala

Room: Zoom Only

Coherent-Field Dark Matter: Candidates and Search Methods

• Andreas Ringwald (Deutsches Elektronen-Synchrotron DESY)

Room: Zoom Only

Searching for Dark States with Nonlinear Optics

• Roni Harnik (Fermilab)

Room: Zoom Only

Fundamental tests of Quantum Mechanics

• Angelo Bassi (Department of Physics - University of Trieste)

Room: Zoom Only

Quantum Metrology Assisted Experiments at the Antiproton Decelerator Facility of CERN

• Stefan Ulmer (RIKEN (JP))

Room: Zoom Only

Direct detection of light dark matter with quantum materials and sensors

• Tongyan Lin

Room: Zoom Only

Quantum sensitivity limits of nuclear magnetic resonance searches for axion-like dark matter

• Alex Sushkov (Boston University)

Room: Zoom Only

Optimal metrology with variational quantum circuits on trapped ions: theory and experiment

• Christian Marciniak (University Innsbruck)
• Raphael Kaubruegger

Room: Zoom Only

The piezoaxionic effect

• Asimina Arvanitaki (PI - Perimeter Institute for Theoretical Physics (CA))

Room: Zoom Only

Navigating Quantum Systems to Detect Ultra-Cold Neutrinos from the Big Bang

• Chris Tully (Princeton University (US))

Room: Zoom Only

Atom Interferometry with MAGIS-100 and AION

• Jeremiah Mitchell (University of Cambridge)

Room: Zoom Only

Quantum sensors from the tabletop to the Universe

• Jonathan R. Ellis (University of London (GB))

Room: Zoom Only

Particle Physics Circa 2021

• Savas Dimopoulos (Unknown)

Room: Zoom Only

Welcome

• Dorota Maria Grabowska (CERN)

Room: Zoom Only

From Quantum Links to D-Theory: A Resource Efficient Framework for the Quantum Simulation of Gauge Theories

• Uwe-Jens Wiese (Bern University)

Room: Zoom Only Quantum link models provide an extension of Wilson's lattice gauge theory in which the link variables have operator-valued entries. For example, in a U(1) quantum link model the link variables are raising and lowering operators of quantum spins that belong to a link-based SU(2) embedding algebra. For non-Abelian SU(N), Spin(N), or Sp(N) quantum link models, the embedding algebras are SU(2N), Spin(2N), and Sp(2N), respectively. In contrast to Wilson's framework, quantum link models can be realized in a finite-dimensional link Hilbert space corresponding to a representation of the embedding algebra. This is well suited for a resource efficient implementation of quantum link models in quantum simulation experiments. The quantum link dynamics can be embodied with a finite number of well-controlled states of ultra-cold matter, including atoms in an optical lattice, ions in a trap, or quantum circuits. For example, using dual variables, a densely encoded quantum circuit has recently been constructed for a (2+1)-d U(1) quantum link model on a triangular lattice that shows qualitatively new nematic phases with rich confining dynamics. Quantum spins and quantum links are discrete quantum variables which give rise to collective low-energy excitations. In (2+1)-d, SU(N) quantum spins give rise to massless Goldstone bosons which undergo dimensional reduction to (1+1)-d asymptotically free CP(N-1) models. This can be realized in quantum simulation experiments with alkaline-earth atoms in an optical lattice. In (3+1)-d, Abelian quantum links give rise to massless photons which undergo dimensional reduction to (2+1)-d confining U(1) gauge theory, which can be embodied with spin-ice. In (4+1)-d, non-Abelian quantum links give rise to massless gluons which undergo dimensional reduction to (3+1)-d Yang-Mills theory. Quarks are naturally included as domain wall fermions. The dimensional reduction of discrete quantum variables defines D-theory, in which quantum field theories emerge from a minimal set of degrees of freedom, thus enabling resource efficient implementations in quantum simulation experiments. D-theory provides a concrete vision how to realize the ultimate long-term goal of quantum simulating QCD.

Quantum simulation for nuclear physics

• Zohreh Davoudi

Room: Zoom Only A vigorous program has formed in recent years in various physics disciplines to take advantage of near-term and future quantum-simulation and quantum-computing hardware to study complex quantum many-body systems, building upon the vision of Richard Feynman. Such activities have also started in nuclear physics, hoping to bring new and powerful experimental and computational tools to address a range of challenging problems in strongly interacting nuclear many-body systems. In this talk, I review a number of important developments, including proposals for simulating strongly interacting quantum field theories, and for quantum computations of hadron and nuclear structure. The hardware technologies that are expected to enable both the analog simulations and the digital quantum computations of these problems will be enumerated, and the case for hardware co-design in the upcoming years will be motivated.

Measurement-based eigensolvers for problems in high energy physics

• Luca Dellantonio

Room: Zoom Only Variational quantum eigensolvers (VQEs) combine classical optimization with efficient cost function evaluations on quantum computers. We propose a new approach to VQEs using the principles of measurement-based quantum computation. This strategy uses entangled resource states and local measurements. We present two measurement-based VQE schemes. The first introduces a new approach for constructing variational families. The second provides a translation of circuit-based to measurement-based schemes. For each scheme, we provide an application in high energy physics, namely the Schwinger model and Z_2 lattice gauge theory.

Dimensional Expressivity Analysis of Parametric Quantum Circuits

• Lena Funcke (Perimeter Institute)

Room: Zoom Only Parametric quantum circuits play a crucial role in the performance of many variational quantum algorithms. To successfully implement such algorithms, one must design efficient quantum circuits that sufficiently approximate the solution space while maintaining a low parameter count and circuit depth. In this talk, we present a method to analyze the dimensional expressivity of parametric quantum circuits. This technique allows for identifying superfluous parameters in the circuit layout and for obtaining a maximally expressive ansatz with a minimum number of parameters. Using a hybrid quantum-classical approach, we show how to efficiently implement the expressivity analysis using quantum hardware, and we provide a proof of principle demonstration of this procedure on IBM's quantum hardware. We also discuss the effect of symmetries and demonstrate how to incorporate or remove symmetries from the parametrized ansatz.

High-energy physics at ultracold temperatures – quantum simulation of lattice gauge theories with cold atoms

• Philipp Hauke

Room: Zoom Only Despite the importance of gauge theories for modern physics, solving their out-of-equilibrium dynamics on classical computers is extremely challenging. This difficulty is currently stimulating a worldwide effort to implement them in dedicated quantum simulators. In this talk, I will discuss recent progress towards quantum simulation of gauge theories using ultracold atoms. I will show recent breakthroughs to overcome the main challenge, the realization of a dynamics that respects gauge symmetry. In particular, I will present a recent experiment based on engineering of suitable energy penalties in an optical lattice, which has realized a many-body gauge theory in a 71-site Hubbard model and has certified the fulfilment of Gauss’s law for the first time. Further, I will discuss recent progress in understanding gauge breaking errors in this and related models as well as possibilities to mitigate them. I will also illustrate some of the fascinating physics attainable in quantum simulators of gauge theories even for simple target models and with realistic resources, such as dynamical topological quantum phase transitions. Finally, I will discuss the state of art and common issues of gauge quantum simulation, and thus aim at outlining a roadmap towards mature and practically relevant quantum simulation of gauge theories.

Cold atoms meet lattice gauge theory

• Maciej Lewenstein

Room: Zoom Only The central idea of this review talk is to consider quantum field theory models relevant for particle physics and replace the fermionic matter in these models by a bosonic one. This is mostly motivated by the fact that bosons are more "accessible"' and easier to manipulate for experimentalists, but this "substitution'" also leads to new physics and novel phenomena. It allows us to gain new information about among other things confinement and the dynamics of the deconfinement transition. We will thus consider bosons in dynamical lattices corresponding to the bosonic Schwinger or Z2 Bose-Hubbard models. Another central idea of this review concerns atomic simulators of paradigmatic models of particle physics theory such as the Creutz-Hubbard ladder, or Gross-Neveu-Wilson and Wilson-Hubbard models. Finally, we will briefly describe our efforts to design experimentally friendly simulators of these and other models relevant for particle physics.

3D-integrated superconducting quantum circuits

• Peter Leek (University of Oxford)

Room: Zoom Only

Application of Quantum Machine Learning to High Energy Physics Analysis at the LHC using Quantum Computer Simulators and Hardware

• Sau Lan Wu (University of Wisconsin Madison (US))

Room: Zoom Only

Quantum Computing for High Energy Colliders

• Christian Walter Bauer (Lawrence Berkeley National Lab. (US))

Room: Zoom Only

Noisy Intermediate-Scale Quantum algorithms

• Alba Cervera-Lierta

Room: Zoom Only A universal fault-tolerant quantum computer that can solve efficiently problems such as integer factorization and unstructured database search requires millions of qubits with low error rates and long coherence times. While the experimental advancement towards realizing such devices will potentially take decades of research, noisy intermediate-scale quantum (NISQ) computers already exist. These computers are composed of hundreds of noisy qubits, i.e. qubits that are not error-corrected, and therefore perform imperfect operations in a limited coherence time. In the search for quantum advantage with these devices, algorithms have been proposed for applications in various disciplines spanning physics, machine learning, quantum chemistry and combinatorial optimization. The goal of such algorithms is to leverage the limited available resources to perform classically challenging tasks. In this talk, I provide an overview of NISQ algorithms, their limitations and potential advantages.

Towards simulating 2D effects in lattice gauge theories on a quantum computer

• Christine Muschik (University of Waterloo)

Room: Zoom Only

Quantum Gravity in the Lab

• Adam Brown

Room: Zoom Only

Thoughts about the Interface

• Martin Savage (Institute for Nuclear Theory)

Room: Zoom Only