RESEARCH
Quantum Materials, Correlated-electron systems, Disordered magnetic systems, High entropy alloys
Quantum Magnetism
Quantum magnetism lies at the frontier of condensed matter physics, where electron spins organize not only into conventional ferromagnetic or antiferromagnetic order but also into states driven by quantum fluctuations and entanglement. These include singlet ground states, frustrated magnets, spin liquids, and hybrid spin–lattice excitations that cannot be captured by classical descriptions. My work combines advanced neutron and X-ray scattering with theoretical modeling to expose how chemical tuning, strain, and disorder reshape spin correlations and magnetic excitations. By disentangling these interactions, I aim to uncover fundamental mechanisms of quantum order and disorder with implications for novel spin-based functionality.
G. Yumnam, et al. Adv. Sci. (2021)
G. Yumnam, et al. Cell Rep. Phys. Sci (2025)
Correlated Electron Systems
Correlation, at its essence, refers to the collective behavior of many entities acting in concert—whether in the synchrony of a symphony orchestra, the coordinated flight of a flock of birds, or the ordered motion of a school of fish. In quantum materials, electrons likewise do not behave as independent particles but as strongly interacting entities whose charge, spin, orbital, and lattice degrees of freedom are entangled. These correlations give rise to emergent states beyond the scope of single-particle physics, including unconventional magnetism, high-temperature superconductivity, metal–insulator transitions, and novel quantum excitations. Understanding these systems is key to revealing how collective electron behavior shapes new phases of matter and drives the search for functional quantum materials.
Neutron Scattering probe of Unconventional Magnetism
Spin and lattice excitations are fundamental excitation that are otherwise challenging to probe, however neutron scattering is an excellent probe for both types of excitations. Neutrons are also the only probe that can convincingly probe any hybridization between the spin-lattice excitations or with any other type of excitations. Using neutron scattering and complementary techniques like X-rays, we study the spin-lattice coupling and other types of excitations in unconventional magnets.
