FRG 3 - Quantum Information Processing

Focus Research Group 3 will utilize Bose-Einstein condensates for the implementation of quantum emulation and quantum computation, which have applications in fundamental problems of strongly correlated, many-body physics and can potentially allow quantum computation above the ultra-low temperature regime that limits current platforms.

Researchers

Jonathan Wrubel, Creighton Physics (group leader)
Jeremy Armstrong, UNK Physics
Wai-Ning Mei, UNO Physics
Renat Sabirianov, UNO Physics
Thomas Wong, Creighton Physics

Research Thrust 1:

Quantum Emulation

Bose Einstein condensates (BECs) are ideal platforms for working out the consequences of a wide variety of ideal quantum Hamiltonians. This kind of quantum emulation uses the BEC to simulate phases or physics relevant to other more complicated systems that cannot be calculated easily with digital computers. BECs are powerful tools for quantum emulation because they form effectively zero-temperature quantum materials with perfect coherence. These complex quantum systems will be explored experimentally in ultracold atoms and in exciton-polaritons, as well as explored theoretically.

Sketch of the energies of the radio-frequency Feshbach resonance in 41K. — **Fig.:** Sketch of the energies of the radio-frequency Feshbach resonance in ⁴¹K.

Research Thrust 2:

Quantum Computation

Quantum computers are known to outperform classical computers at a variety of tasks, including breaking public-key cryptographic systems, searching databases, and finding approximate solutions to optimization problems. Governments across the world have recognized quantum computing's potential for ushering a technological revolution by passing strategic legislation funding for its research and development. In the U.S., the National Quantum Initiative Act was passed by Congress in December 2018 and quickly signed into law. In this thrust, FRG 3 proposes to investigate quantum algorithms based on quantum walks and a new qubit based on crosswire quantum dots.

Figure (a) Schematic diagram of crossed wire configuration of a qubit. Two crosswire QDs are coupled through a bridge of distance d. The ground state (left) and first excited state (right) have even-odd parity. The energy separation between these states is controlled by the width of the crosswire and the size of the bridge d. Figure (b) Schematic representation of energies of the two-level-atom-like system coupled to the 1D waveguide characterized by decay rate (Γ1D) and waveguide mode wavenumber (k1D). — **Fig.: (a)** Schematic diagram of crossed wire configuration of a qubit. Two crosswire QDs are coupled through a bridge of distance d. The ground state (left) and first excited state (right) have even-odd parity. The energy separation between these states is controlled by the width of the crosswire and the size of the bridge d. **(b)** Schematic representation of energies of the two-level-atom-like system coupled to the 1D waveguide characterized by decay rate (Γ_1D) and waveguide mode wavenumber (k1_D).