Another Round of Breaking and Making Quantum Money: How to Not Build It from Lattices, and More
Public verification of quantum money has been one of the central objects in quantum cryptography ever since Wiesner's pioneering idea of using quantum mechanics to construct banknotes against counterfeiting. So far, we do not know any publicly-verifiable quantum money scheme that is provably secure from standard assumptions.
In this talk, we provide both negative and positive results for publicly verifiable quantum money.
Towards Provably Efficient Quantum Algorithms for Nonlinear Dynamics and Large-scale Machine Learning Models
Large machine learning models are revolutionary technologies of artificial intelligence whose bottlenecks include huge computational expenses, power, and time used both in the pre-training and fine-tuning process. Based on quantum Carleman linearization and shadow tomography (QRAM is not necessary), we design the first quantum algorithm for training classical sparse neural networks with end-to-end settings.
Alumnus Jonathan Hoffman Heads Toward New Horizon in Navigation Science
As a PhD graduation present, UMD physics alumnus Jonathan Hoffman’s adviser gave him a signed copy of the book Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. The book follows John Harrison, an 18th-century carpenter who took it upon himself to solve what was known as the longitude problem by building a series of 5 clocks, the best timekeepers to date. Eight years later, as a program manager at the Defense Advanced Research Projects Agency (DARPA), Hoffman has started a new program called H6 seeking to build a spiritual successor to Harrison’s clocks: a “6th clock” that would be a compact, affordable, and precise device that would help navigate in situations where a GPS signal is unavailable.
Quantum Hall physics in light-matter hybrid systems
In this seminar, I will present and discuss recent results from one of the experimental research lines at Hafezi group: quantum Hall physics in semiconductor microcavities. A 2D charge gas (2DCG) operating in the quantum Hall regime represents one of the few examples of macroscopic quantum behavior. Other examples in this short list are Bose-Einstein condensation and superconductivity. Typically, the experimental study of the quantum Hall effect relies on transport.
Simulating Mesonic Scattering Processes on Trapped-Ion Simulators
Obtaining real-time dynamics of particle collisions is a long-standing goal in high energy and nuclear physics. Developing protocols to simulate lattice gauge theories on quantum simulators offer a strategy to probe these scattering processes. Both long-range and short-range quantum Ising chains exhibit the confinement of quasiparticles, analogous to the high-energy confinement of quarks in bound, meson states. In this talk, we will discuss a proposal to simulate meson scattering in a trapped-ion simulator.
Protecting Superconducting Qubits from Environmental Poisoning
Abstract: Superconducting circuits are an attractive system for forming qubits in a quantum computer because of the natural energy gap to excitations in the superconductor. However, experimentally it is observed that superconducting qubits have excitations above the superconducting ground state, known as quasiparticles, at a density that is many orders of magnitude above the expected equilibrium level.
Towards cross-platform verification in quantum networks
Intermediate-scale quantum devices are becoming more reliable, and may soon be harnessed to solve useful computational tasks. At the same time, common classical methods used to verify their computational output become intractable due to their prohibitive scaling of required resources with system size. In this talk, I aim at giving an overview of selected verification strategies. Inspired by recent experimental progress, we analyze efficient cross-platform verification protocols for quantum states and computations.
The Riemann Zeta Function, Poincare Recurrence, and Quantum Chaos
The spectral form factor is an important diagnostic of quantum chaos and thermalization. In this talk we will dive into a surprising duality between short time behavior and exponentially late-time behavior, with a cameo from the Riemann zeta function.
(Pizza and refreshments will be served after the talk.)