The Jeong Group

Banner shaped image illustrating condensed matter physics research

Our research is focused on magnetic phenomena in solid quantum matter such as emergence of quasi-particles (e.g., magnons, spinons), quantum criticality and formation of macroscopic quantum-entangled states (e.g., spin liquid). 

Questions

Questions

on quantum matter

“Are there ultimate limits to the types of quantum matter that can exist in the universe? ... How do the exotic behaviours of quantum matter give way to the familiar properties of everyday materials? ... What principles govern the behaviour of quantum matter when driven away from equilibrium?”

Seeking answers to these questions, we find that Magnetic Phenomena in Solid Quantum Matter are particularly insightful - which is our core research subject.

Projects

 Our long term projects include:

  • Synthesis of crystalline quantum materials: We use i) chemical vapour transport method (in collaboration with Dr Matt Coak) to grow quantum spin-liquid candidate materials (e.g., honeycomb lattice RuCl3) and ii) solution method (in collaboration with Dr Dominik Kubicki, Chemistry) to grow coordination polymer-based quantum magnets (e.g., spin-1/2 chain CuPzN).

  • Atomic-scale imaging of quantum materials: We use high-resolution and scanning tunneling electron microscopy to visualise local structure of quantum materials at sub-angstrom resolution (in collaboration with Prof. Hu Young Jeong (UNIST, Korea). Funded by Royal Society (International Exchange).

  • Atomic-scale spectroscopy of quantum magnets: Funded by EPSRC (Strategic Infrastructure)

  • Strain tuning of quantum magnetism: Funded by Royal Society (Research Grant), Univ. Birmingham (BRIDGE Seed). 

  • Spin transport in low-dimensional magnets: Funded by EPSRC (New Investigator Award).

  • Quantum light-matter interaction in superconducting resonators

Expertise

We have expertise in (and in-house capability of):

  • Nuclear Magnetic Resonance
  • Low temperature physics and cryogenics
  • Magnetic and superconducting materials characterisation

Our group manages some of the shared facilities at the University of Birmingham: 

  • PPMS - Physical Property Measurement System
  • MPMS-3 - Magnetic Property Measurement System
  • ULT-NMR - Ultra-Low-Temperature Nuclear Magnetic Resonance

We perform part of our experiments at large national and international facilities:

  • Muon spin rotation and relaxation: ISIS (Oxfordshire), PSI (Villigen, Switzerland)
  • X-ray spectroscopy: Diamond Light Source (Oxfordshire)
  • High field NMR: LNCMI (Grenoble, France), Uni Warwick

Serving the society

Fundamental physics with cryogenics

Our group is part of the QSNET consortium, which delivers a project of the national programme, Quantum Technologies for Fundamental Physics, jointly funded by EPSRC and STFC. The goal of the QSNET project is to test stability of fundamental constants such as the fine structure constant and the mass ratio of the proton to the electron. The plan is to link different kinds of Quantum Clocks at different locations. At Birmingham, a highly charged-ion clock using a cryogenic ion trap is under construction, for which we share our expertise in cryogenic techniques.

G. Barontini et al., EPJ Quantum Technology, 9(1), 12 (2022).

Cold energy using magnetic materials

One can raise or lower the temperature of certain materials by applying or removing a magnetic field, respectively. This is called the Magneto-Caloric Effect, which forms a basis of cleaner and more efficient cooling or refrigeration. We share our expertise in magnetic characterisation to support researchers from chemistry, materials and metallurgy for their new designs (e.g., involving frustration) and processing (e.g., additive manufacturing or 3D printing) of advanced magneto-caloric materials.

J. Head et al., Chemistry of Materials, 32 (23), 10184 (2020).

Public outreach in physical sciences

Mingee has published dozens of columns and articles for public awareness of physical sciences. They appeared in a popular webzine, Crossroads, published by the Asia-Pacific Centre for Theoretical Physics, and also in major Korean newspapers including Hankyoreh and Munhwa-ilbo. We plan to do such activities in English to reach out more broadly.