Kiosk 2

Abstract: Ever wondered how we perceive the world around us? How do our eyes detect light and how does our brain interpret what our eyes see? In this discussion, we will investigate how human vision and perception works, as well as how it can be manipulated through visual illusions. We will also explore how human vision differs from the vision of other animals such as dogs, birds, and insects.

The Department of Physics proudly presents the Saturday Physics Series, lectures geared toward high school students and adults to highlight the exciting research and practical potential of physics. 
 

All lectures are free and open to the public.

Abstract: I'll tell you about some of our recent work on preparing tensor network states on quantum devices. The general research question is motivated by the observation that ground states of gapped (and often also gapless) models are well described by tensor networks. To explore and simulate such states on quantum devices, we need to find ways to prepare them efficiently. More recently I've also wondered about what we could say about computational complexity (both quantum and classical) of tensor network states and I'll talk about some results in this direction as well. This is based on arXiv:2107.05873, 2209.01230, 2307.01696, 2402.07975 and ongoing work together with Zhi-Yuan Wei, Georgios Styliaris, Rahul Trivedi, Freek Witteveen and Ignacio Cirac.

The scale of electronic structure calculations feasible on current or near-term quantum hardware is constrained by several inherent limitations, including coherence time, qubit count and connectivity, and device noise. All these limitations taken together severely impact the number of qubits that may be put to work constructively for chemical applications. While we have routine access to quantum computing devices exceeding 100 qubits, only a handful of these can be utilized effectively. This motivates the need for embedding and subspace techniques, in order to tackle sizeable molecular systems using the modest scale of quantum computers available to us today. I will discuss these approaches, which include the use of Quantum Mechanics/Molecular Mechanics, Projection-Based Embedding, frozen-core approximations, qubit tapering and contextual subspace methods.

A brief biography: Peter Coveney is a Professor of Physical Chemistry, Honorary Professor of Computer Science, and Director of the Centre for Computational Science (CCS) and Associate Director of the Advanced Research Computing Centre at University College London (UCL). He is also Professor of Applied High Performance Computing at the University of Amsterdam (UvA) and Professor Adjunct at the Yale School of Medicine, Yale University. He is a Fellow of the Royal Academy of Engineering and Member of Academia Europaea. Dr Coveney has made outstanding contributions across a wide range of scientific and engineering fields, including physics, chemistry, chemical engineering, materials, computer science, high performance computing and biomedicine, much of it harnessing the power of supercomputing to conduct original research at unprecedented space and time scales. He has shown influential leadership across these fields, manifested through running multiple initiatives and multi-partner interdisciplinary grants, in the UK, Europe and the US. In addition to his scientific writings and publications, he has published three books for the general reader, The Arrow of Time, Frontiers of Complexity and Virtual You.

Forthcoming

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Abstract:

I will discuss the quantification of uncertainty in predictive models arising in physics-based models and models based on machine-learning. Applications will include predictions of the impact of pandemics, the design of advanced materials, discovery of new drugs and the behaviour of turbulent fluids. The curse of dimensionality has hitherto circumscribed the systematic study of more complex natural and artificial systems but the advent of scalable approaches is now starting to change things. A paradigm case which is widely used within the scientific community across all fields from physics and chemistry to materials, life and medical sciences is classical molecular dynamics. I will describe how we are now able to make global rankings of the sensitivity of quantities of interest to the many hundreds to thousands of parameters which are used in these models. In particular, we are able to rank the importance of all the interaction potential (force field) parameters. I will compare and contrast such approaches with the situation which pertains when attempts are made to replace these force fields with machine learned versions in the hope of making them more widely applicable. 

Forthcoming

Abstract: The rare earth elements, hidden at the bottom of the periodic table and long neglected, have risen to prominence at the end of the 20th century. Their unique electronic configuration form the basis for a variety of lasers, photonic applications, strong and exotic magnetism, defining many modern technologies. I will tell a story connecting from the basic science of the geology of Colorado and rare earth and other rare element mineralogy, to our technological and societal dependence and questions of strategic element security. 

The Department of Physics proudly presents the Saturday Physics Series, lectures geared toward high school students and adults to highlight the exciting research and practical potential of physics. 

All lectures are free and open to the public.

Abstract: Polar molecules trapped in programmable optical tweezer arrays are an emerging platform for quantum science. In this talk, I will report our group’s work on advancing quantum control of molecular tweezer arrays and our first experiments on using these arrays for quantum information processing and simulation of quantum many-body Hamiltonians.I will first briefly present our work that establishes the essential building blocks for quantum science in this platform. These include preparation and detection of single molecules, control of their interactions, and the deterministic entanglement of pairs of molecules. Next, I will report on our subsequent efforts to further advance molecular control to a level necessary for quantum applications. In particular, I will focus on our recent work that uses mid-circuit measurement to both improve quantum state preparation and to implement erasure error detection and conversion in molecular qubits. Lastly, I will present recent work on simulating interacting quantum spin chains using 1D molecular arrays. Specifically, I will report on several phenomena that we have observed in the quantum dynamics of 1/r3 XX/XXZ/XYZ spin chains. These include coherent quantum walks of single spin excitations, appearance of repulsive bound states, and coherent pair creation and annihilation.

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All seminars are held in the CASE Auditorium. Light refreshments will be served starting at 3:30 p.m. Talk begins at 4 p.m.
This seminar series is sponsored by CUbit with generous support of the Caruso Foundation.

Forthcoming