Collective light scattering in cold atomic ensembles: super-radiance, driven Dicke model and correlations
Abstract: This talk will present our work on the observation of super-radiance in a cloud of cold atoms driven by a laser. We start from an elongated cloud of laser cooled atoms that we excite either perpendicularly or along its main axis. This situation bears some similarities with cavity quantum electrodynamics: here the cavity mode is replaced by the diffraction mode of the elongated cloud. We observe superradiant pulses of light after population inversion.
Universal dynamics of nonequilibrium quantum matter
Abstract: Today’s programmable quantum simulators offer versatile platforms for exploring many-body phases and dynamics in correlated quantum systems. In this talk, we present some new—and surprising—insights into nonequilibrium quantum dynamics inspired by such recent experimental advances. First, we focus on understanding the evolution of closed quantum systems driven through a phase transition, which is crucial for quantum state preparation and adiabatic algorithms.
Reducing circuit depth of commuting Pauli Strings diagonalization
A variety of quantum algorithms employ Pauli operators as a convenient basis for studying the spectrum or evolution of Hamiltonians or measuring multibody observables. One strategy to reduce circuit depth in such algorithms involves simultaneous diagonalization of Pauli operators generating unitary evolution operators or observables of interest.
On the optimal error exponents for classical and quantum antidistinguishability
The concept of antidistinguishability of quantum states has been studied to investigate foundational questions in quantum mechanics. It is also called quantum state elimination, because the goal of such a protocol is to guess which state, among finitely many chosen at random, the system is not prepared in (that is, it can be thought of as the first step in a process of elimination). Antidistinguishability has been used to investigate the reality of quantum states, ruling out psi-epistemic ontological models of quantum mechanics [Pusey et al., Nat.
Quantum-enhanced electric field sensing using 2D Crystals of over 100 Ions in a Penning Trap
Abstract: Utilizing quantum mechanical effects such as entanglement can allow sensors to have sensitivities below those imposed on purely classical states. As an example, our experiment has utilized entanglement of the spin and collective motion of 2D crystals of over 100 ions in a Penning trap to demonstrate a sensitivity to displacements of 8.8 ± 0.4 decibels below the standard quantum limit [Science 373, 673 (2021)].
Photon-Mediated Interactions in Lattices of Coplanar Waveguide Resonators
Abstract: Circuit quantum electrodynamics (circuit QED) has become one of the main platforms for quantum simulation and computation. One of its notable advantages is its ability to facilitate the study of new regimes of light-matter interactions. This is achieved due to the native strong coupling between superconducting qubits and microwave resonators, and the ability to lithographically define a large variety of resonant microwave structures, for example, photonic crystals.
Photon-Mediated Interactions in Lattices of Coplanar Waveguide Resonators
Circuit quantum electrodynamics (circuit QED) has become one of the main platforms for quantum simulation and computation. One of its notable advantages is its ability to facilitate the study of new regimes of light-matter interactions. This is achieved due to the native strong coupling between superconducting qubits and microwave resonators, and the ability to lithographically define a large variety of resonant microwave structures, for example, photonic crystals.
Ultracold Gases in a Two-Frequency Breathing Lattice
Dissertation Committee Chair: Prof. Steve Rolston
Committee:
Prof. Gretchen Campbell
Prof. Nathan Schine
Prof. Ron Walsworth
Prof. Ki-yong Kim
How to relate quantum position verification to information-theoretic cryptography, and new steps towards practical implementation
The task of quantum position verification (QPV) deploys quantum information with the aim to use a party's position as a cryptographic credential. One well-studied proposed protocol for this task, f-routing, involves a mixture of classical information and a single quantum bit that has to be routed somewhere as a function of the classical information.
Microscopic and Emergent Dynamics of Quantum Information Flows
Abstract: The past fifty years of scientific and technological progress have clearly highlighted information as a physical resource - one that can be traded for heat, work, and other energetic resources. With the ongoing new wave of quantum-based technologies, understanding the microscopic and emergent dynamics of quantum information in many-body quantum systems has thus become a priority.