Center for Correlated Electron Systems

Emergent Phenomena

Emergent Phenomena Group

The Emergent Phenomena Group, led by Prof. Je-Geun Park, is the second group to be established within the IBS Center for Correlated Electron Systems. We focus on studies of strongly correlated electron systems such as transition metal oxides and related materials as well as 2D magnetic materials.
The group consists of three teams: the Materials Team, Van der Waals Team, and Scattering Team. Having these three teams working together allows our group to paint a complete picture of novel materials, studying their crystal and magnetic structure, physical properties and spin dynamics. Our ability to rapidly characterize and investigate the properties of new materials offers crucial feedback to improve the sample preparation, while having a dedicated Materials team ensures a steady supply of new and interesting systems for investigation. We are equipped with state-of-the-art instruments for utilization in all areas of our research topics. Please see the relevant sections of this website for more information on our teams and equipment.
We are generally interested in every area of strongly correlated physics, but focus particularly on magnetic properties. We are currently conducting research into the following selected topics: spin-orbital coupling and interaction between bosonic excitations in transition metal oxides, and low dimensional magnetism.
Materials Team
The Materials Team produces high-quality single-crystalline and polycrystalline samples of interesting, new, and under-investigated materials, to act as the foundation for research into their fundamental physics. We have studied Ru-oxides in order to explore spin-orbit physics, and we are working to expand these research efforts by synthesizing new samples using our new high-pressure anvil furnace.
Van der Waals Team
The Van der Waals Team aims to realize 2D magnetic materials and to provide comprehensive physical property characterization by using lab-based tools such as MPMS, PPMS and several other set-ups available. With these, we measure most of the transport and thermodynamic properties in temperature ranges of 0.3 to 1000 K and magnetic fields up to 14 Tesla.
Scattering Team
The Scattering Team observes and analyzes elementary excitations of various magnetic materials through neutron and X-ray scattering experiments. The main subject this team is currently studying is the interaction between collective excitations such as magnons and phonons in triangular lattice systems. In addition, some pyrochlore and stacked kagome systems are being studied. The team is also working on examining topological excitations, such as topological magnons, in various lattice structures. These types of excitations have recently emerged as a field full of novel physics.
Needless to say, as a materials science group, we are constantly searching for new materials with interesting emergent phenomena.
Prof. Je-Geun Park's photo
Selected Publications
Spontaneous decays of magneto-elastic excitations in noncollinear antiferromagnet (Y,Lu)MnO3
Joosung Oh, Manh Duc Le, Ho-Hyun Nahm, Hasung Sim, Jaehong Jeong, T. G. Perring, Hyungje Woo, Kenji Nakajima, Seiko Ohira-Kawamura, Zahra Yamani, Y. Yoshida, H. Eisaki, S.-W. Cheong, A. L. Chernyshev, and Je-Geun Park
Nature Communications 7, 13146 (2016)
Ising-Type Magnetic Ordering in Atomically Thin FePS3
Jae-Ung Lee, Sungmin Lee, Ji Hoon Ryoo, Soonmin Kang, Tae Yuoon Kim, Pilkwang Kim, Cheol-Hwan Park, Je-Geun Park, and Hyeonsik Cheong
Nano Lett. 16, 7433?7438 (2016)
The low-temperature highly correlated phase in the charge-density-wave 1T-TaS2 compound
Marie Kratochvilova, Adrian D. Hillier, Andrew R. Wildes, Lihai Wang, Sang-Wook Cheong, and Je-Geun Park
NPG Quantum Materials 2, 42 (2017)
Jahn-Teller distortion driven magnetic polarons in magnetite
H. Y. Huang, Z. Y. Chen, R.-P. Wang, F. M. F. de Groot, W. B. Wu, J. Okamoto, J.-S. Zhou, H.-T. Jeng, G. Y. Guo, Je-Geun Park, L. H. Tjeng, C. T. Chen, and D. J. Huang
Nature Communications 8, 15929 (2017)
Charge-spin correlation and self-doped ground state in van der Waals antiferromagnet NiPS3
So Yeun Kim, Tae Yun Kim, Luke J. Sandilands, Soobin Sinn, Min-Cheol Lee, Jaeseok Son, Sungmin Lee, Ki-Young Choi, Wondong Kim, Byeong-Gyu Park, C. Jeon, Hyeong-Do Kim, Cheol-Hwan Park, Je-Geun Park, S. J. Moon, T. W. Noh
Phys. Rev. Lett. 120, 136402 (2018)
Magnetism in two-dimensional van der Waals materials
Kenneth S. Burch, David Mandrus, and Je-Geun Park
Nature 563, 47 (2018)
Suppression of magnetic ordering in XXZ-type antiferromagnetic monolayer NiPS3
Kangwon Kim, Soo Yeon Lim, Jae-Ung Lee, Sungmin Lee, Tae Yun Kim, Kisoo Park, Gun Sang Jeon, Cheol-Hwan Park, Je-Geun Park, and Hyeonsik Cheong
Nature Communications 10, 345 (2019)
Main Equipment
Magentic Property Measurement System (MPMS)

Magentic Property Measurement System (MPMS)

Utilizing SQUID (Superconducting Quantum Interference Device) magnetometer and VSM, our MPMS enables very accurate measurement of magnetic susceptibility (< 10-8 emu). Magnetic field can be varied up to 7 T and down to the ultra-low 0.05 G using a superconducting magnet. With the cooling rate fast enough to reach 1.8 K in less than 30 minutes, wide range of temperature control (1.8 K ~ 400 K) is also available without helium loss using the cryogen-free Dewar. Using MPMS, we have been illuminating magnetic properties of new novel materials precisely.