Introduction to Quantum Computing (CMSC457/PHYS457, Spring 2023)
An introduction to the concept of a quantum computer, including algorithms that outperform classical computation and methods for performing quantum computation reliably in the presence of noise. As this is a multidisciplinary subject, the course will cover basic concepts in theoretical computer science and physics in addition to introducing core quantum computing topics.
Quantum Technology (PHYS720/ENEE789M, Spring 2023)
A good grounding in electromagnetism and quantum mechanics is necessary; familiarity with density matrices and master equations will be helpful. Physical principles behind emerging quantum technologies, from quantum-limited amplifiers to atomic simulators. Examination of current and emerging platforms for quantum technologies, including neutral atom, ion trap, superconducting circuit, photonic, and spin-based approaches. Focus on hurdles for implementing quantum devices for new applications.
It ain’t just a detector: A new class of optical sensors based on Optoelectronic Chromatic Dispersion in photodiodes
Abstract: Light is essential for life as we know it, and the ubiquitous PN-junction is the pervasive light sensor, whether for optical detection or for energy harvesting. Since its inception over 70 years ago, the physics behind the photodiode is now well understood, including its dependence on the illumination wavelength. However, there is a further prominent feature of photodiodes that has been largely overlooked. These devices can exhibit significant and tunable chromatic dispersion, which we call Optoelectronic Chromatic Dispersion (OED).
A Complexity Theory for the Quantum Age?
How hard is it to compress a quantum state? To fast-forward the evolution of a local Hamiltonian? To unscramble the Hawking radiation of a black hole? Traditional complexity theory -- which is centered around decision problems and tasks with classical inputs and outputs -- appears inadequate for reasoning about the complexity of such tasks involving quantum inputs and outputs.
Multi-qubit gates for quantum computing with neutral atoms
Neutral atoms have emerged as a competitive platform for digital quantum simulations and computing. In this talk, we discuss recent results on the design of time-optimal and robust multi-qubit gates for neutral atoms. We present a family of Rydberg blockade gates that are robust against two common experimental imperfections -- intensity inhomogeneity and Doppler shifts – and demonstrate that these gates outperform existing gates for moderate or large imperfections.
Controllability of quantum dot arrays via maximum entropy
Quantum dots are a promising platform to realize practical quantum computing. However, before they can be used as qubits, quantum dots must be carefully tuned to the correct regime in the voltage space to trap individual electrons. Moreover, realizable quantum computing requires tuning of large arrays, which translates to a significant increase in the number of parameters that need to be controlled and calibrated. This necessitates the development of robust and automated methods to bring the device into an operational state.
Quantum simulations with trapped ions: Thermal \lamba\phi^4 field theories and Z2 gauge theories
In this talk, Dr Bermúdez will start by reviewing the recent progress of analog quantum simulators based on crystals of trapped atomic ions. He will discuss recent experiments that exploit both the electronic and vibrational degrees of freedom to simulate spin models and bosonic lattice models.
Quantum Communication and Thermalization, From Theory to Practice
The postulates of quantum mechanics generalize classical probability distributions and thus transmission of information, enabling fundamentally novel protocols for communication and cryptography. These algorithms motivate the deployment of quantum networks, a distributed model of computation where universality and fault-tolerance are often not required. Based on constructions from communication complexity, we design a voting scheme with efficient scaling of quantum communication and computation, and prove its security.
Quantum Enhanced Impulse Measurements and Their Applications in Searches for Dark Matter
Optomechanical systems have enabled a variety of novel sensors that transduce an external force on a mechanical sensor to an optical signal which can be read out through different measurement techniques. Based on recent advances in these sensing technologies, we suggest that heavy dark matter candidates around the Planck mass range could be detected solely through their gravitational interaction.