Exceptional points and their consequences in minimal quantum systems (TRACKING NUMBER 20-000000496)
Abstract
Research Problem and Objectives: We are trying to create fundamentally new ways to construct and control quantumsystems. The evolution of a quantum system is governed by its discrete energies. These energies are almost alwaysassumed to be real, and this guaranteed by a mathematical property called Hermiticity. We are exploring theconsequences of complex energies, allowing non-Hermitian dynamics. These novel consequences arise from thetopology of the Riemann manifolds that describe complex energies and their degeneracies known as exceptionalpoints (EPs). We have recently found a new way to realize EPs in a fully quantum and fully controllable systemcomprising a superconducting circuit. Our objective is to investigate EPs in single, two, and many qubit systemsto demonstrate novel functionalities in quantum information processing enabled by EPs.Technical Approaches: The proposed research consists of five interdependent, logically proximate aims. They arethe investigation of Liouvillian EPs, realization of the quantum Hatano-Nelson model, demonstration of EPs inparametric amplifier circuits, harnessing Floquet control over EPs, and exploiting EPs in two- and many-qubitsystems to control quantum transduction, steer many-qubit systems toward entangled states through dissipation,and probe non-Hermitian quantum materials. The theoretical modeling will be informed by, and in turn will inform,experimental feasibility. We will use analytical modeling through non-Hermitian dynamics and Lindblad equationsand exact diagonalization method; efficient theoretical and numerical exploration of the parameter space willdetermine optimal regions in which experiments, which are necessarily harder, will take place. Experimental workwill focus on microwave frequency superconducting quantum circuits utilizing both parametric amplifier andtransmon circuits based on Josephson junctions as a source of low loss nonlinearity. This circuit quantumelectrodynamics architecture is a leading platform for quantum information processing, ensuring that experimentaladvances readily translate to practical quantum devices.Anticipated Outcome and Impact on DoD Capabilities: This proposal addresses fundamental research in to new areasof quantum dynamics with applications in quantum sensing and quantum information processing. Broadly speaking,the research tackles how dissipation, which is ubiquitous in any practical quantum system, forms a new resourcefor quantum control. Our proposed research has several clear connections with the quantum information sciencemission. They include the possibility of developing quantum sensors that leverage the purported advantages ofEPs; the possibility of enhancing quantum coherence through coherent, non-Hermitian dynamics; the possibility ofsteering quantum systems towards entangled many-body states through EPs; and the prospect of harnessing EPs toenhance quantum transduction. Ultimately, this research program has the potential to realize fault tolerantquantum operations based on topologically protected geometric phases accumulated on quantum states undergoingnon-Hermitian dynamics.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 05, 2021
- Source ID
- N000142112630
Entities
People
- Yogesh N. Joglekar
Organizations
- Indiana University
- Office of Naval Research
- United States Navy