FRG 2 - Quantum Technologies

Focus Research Group 2 will address current limitations impeding quantum technology by exploring solid-state spin qubits for quantum sensing and metrology, and photons for ultrafast, compact, and low-power quantum communication nanophotonic devices.

Researchers

  • Abdelghani Laraoui, UNL MME (group leader)
  • Christos Argyropoulos, UNL ECE
  • Wei Bao, UNL ECE
  • Sy-Hwang Liou, UNL Physics
  • Eva Schubert, UNL ECE
  • Mathias Schubert, UNL ECE
  • Jonathan Wrubel, Creighton Physics

Research Thrust 1:

Quantum Sensing and Metrology

Quantum sensing is the use of qubits to detect environmental parameters. Quantum sensors based on atomic vapor cells are already used commercially in geology and navigation systems. The introduction of new quantum sensors, based on solid-state qubits, opens new applications with significant societal impact, including materials discovery, biosensing, and solid-state device characterization. In particular, the NV center in diamond, a spin-1 defect, is among the leading quantum sensors. It has an optically addressable electron spin with millisecond quantum coherence even at room temperature that enabled the first detection of single protons and proteins. NV centers also enabled sub-micron nuclear magnetic resonance (NMR) spectroscopy and demonstrate entanglement between distant (>1 km) spin qubits with high (> 90%) fidelity. Thrust 1 will use NV to study spin-magnon interactions in magnonic devices (Laraoui) and perform LF magnetic resonance spectroscopy, and develop THz-EPR-E to investigate new solid-state qubits in UWBG semiconductors with superior properties to NV.

Figure (a) Energy-levels of NV. Figure (b) Schematic of ODMR microscope. Figure (c) A diamond film mounted on a YIG disk. Figure (d) NV ODMR peaks on (off) YIG, at applied fields of 180 G (160 G). Figure (e) Magnon driven Rabi oscillations in NV spins (dip 1 in (d)).
Fig.: (a) Energy-levels of NV. (b) Schematic of ODMR microscope. (c) A diamond film mounted on a YIG disk. (d) NV ODMR peaks on (off) YIG, at applied fields of 180 G (160 G). (e) Magnon driven Rabi oscillations in NV spins (dip 1 in (d)).

Research Thrust 2:

Quantum Communication

Quantum photonics, such as boson sampling and quantum walks using single photon sources, and single-photon detectors have been one of the leading platforms for quantum computation and quantum communication. However, it is difficult to design these nanoscale technologies, because of fundamental physical limitations in the materials used, including the diffraction limit of light and extremely weak light-matter interactions at the nanoscale. Thrust 2 will design new hybrid composite photonic nanostructures made of ultrathin sub-nm dielectric oxide layers along ultrasmooth metals, perovskites, and solid-state emitters in UWBG semiconductors and 2D materials. FRG 2 will utilize unique theoretical, nanofabrication, and experimental photonic expertise to explore the complex behavior of these new structures. Such research promises to overcome current limitations impeding the design of quantum communication technologies by leading to the efficient control and enhancement of photon absorption; spontaneous and stimulated emission rates causing single or multiple photon streams, and other quantum optical, nonlinear, and topological processes.

Enhanced nonlinear (a) and quantum (b) optical effects based on localized gap-plasmon nanostructures. (c) Arrays of GLAD fabricated Au-Si slanted nanocolumns and Ag-Si nanohelices to achieve enhanced chiral response. (d) Nonlinear helical metasurfaces for enhanced circularly-polarized harmonic generation.
Fig.: Enhanced nonlinear (a) and quantum (b) optical effects based on localized gap-plasmon nanostructures. (c) Arrays of GLAD fabricated Au-Si slanted nanocolumns and Ag-Si nanohelices to achieve enhanced chiral response. (d) Nonlinear helical metasurfaces for enhanced circularly-polarized harmonic generation.

FRG-2 Selected Publications will appear here: