Focus Research Group 1

FRG 1 - Quantum Materials

Focus Research Group 1 will explore the emergent phenomena driven by the complex interplay between correlation, topology, and spin-orbit coupling in a variety of quantum and topological materials.

Researchers

  • Christian Binek, UNL Physics (Scientific Director)
  • Peter Dowben, UNL Physics
  • Yinsheng Guo, UNL Chemistry
  • Xia Hong, UNL Physics (group leader)
  • Alexey Kovalev, UNL Physics
  • Rebecca Lai, UNL Chemistry (E/O leader)
  • Robert Streubel, UNL Physics
  • Evgeny Tsymbal, UNL Physics
  • Xiaoshan Xu, UNL Physics

Research Thrust 1:

Correlation, Topological, and Emergent Phenomena in Quantum Materials

Thrust 1 focuses on nanoscale thin films and heterostructures hosting topological antiferromagnetic (AFM) states, Berry phase effects in real and reciprocal spaces, and correlation-driven phenomena. FRG 1 seeks novel approaches to achieve energy efficient control of these quantum states, including the lift of Dirac nodal lines via Néel vector switching, novel tunneling behaviors, and electrical field effect control of topological Hall effects, which will be complemented with theoretical modeling.

Figure (a) 3D band structure (top) and 2D spin projection (bottom) in BiInO3. Figure (b) Schematic of a tunnel junction. Figure (c) Second harmonic generation mapping of 1L MoS2 on PZT. (d) Schematic of a Hall transistor hosting a Néel type skyrmion. Figure (e) Topological Hall effect in (110) NCO.
Fig.: (a) 3D band structure (top) and 2D spin projection (bottom) in BiInO3. (b) Schematic of a tunnel junction. (c) Second harmonic generation mapping of 1L MoS2 on PZT. (d) Schematic of a Hall transistor hosting a Néel type skyrmion. (e) Topological Hall effect in (110) NCO.

Research Thrust 2:

Magnoelectric and Valley Control of Layered, 2D Materials

Thrust 2 explores magnetoelectric and valley control of topological phases and valley-spin locking in layered 2D vdW materials, facilitating the development of a versatile platform for both charge and spin based topological quantum computing.

Figure (a) Schematic setup for the detection of the VHE in chromia with two antiparallel aligned domains of the surface magnetization. Figure (b) Working principle of the valley spin valve, where Ez can be supplied by a ferroelectric gate.
Fig.: (a) Schematic setup for the detection of the VHE in chromia with two antiparallel aligned domains of the surface magnetization. (b) Working principle of the valley spin valve, where Ez can be supplied by a ferroelectric gate.

Research Thrust 3:

New Materials for Spin-qubit Systems

Thrust 3 utilizes chemistry-based, bottom-up approaches to design material platforms that can host spin-qubits, seeks voltage control of molecular spin states for quantum logic operations, and explores their potential for achieving scalable quantum information storage and transfer.

FSchematics of (a) molecular qubit-linker-qubit structure, (b) SCO molecule Fe[H2B(pz)2]2(bipy), (c) RT conductance vs. applied voltage of a 20 nm Fe[H2B(pz)2]2(bipy) device (inset) on a uniform C5H2O5 film, and (d) 3D MOF of formula (VO (TCPP-Zn2-bpy)) (TCPP = tetracarboxyl- phenylporphyrinate; bpy=4,4′-bipyridyl).
Fig.: Schematics of (a) molecular qubit-linker-qubit structure, (b) SCO molecule Fe[H2B(pz)2]2(bipy), (c) RT conductance vs. applied voltage of a 20 nm Fe[H2B(pz)2]2(bipy) device (inset) on a uniform C5H2O5 film, and (d) 3D MOF of formula (VO (TCPP-Zn2-bpy)) (TCPP = tetracarboxyl- phenylporphyrinate; bpy=4,4′-bipyridyl).

FRG-1 Selected Publications