February 11, 2025 11:30 am - 12:30 pm ET
Condensed Matter Seminar
LGRT 1033

Quantum Materials with Reduced Dimensionality

Mengke Liu, Harvard University

In the emerging post-Silicon era, the search for revolutionary materials necessitates principles that transcend those underpinning silicon's success. Quantum materials with reduced dimensionality hold immense promise due to their reduced symmetry, enhanced electron correlation, and unprecedented tunability. Unlike in silicon, electrons in these materials exhibit enhanced correlations and tend to behave collectively, giving rise to a wide range of novel quantum phenomena—such as high-temperature superconductivity and the fractional quantum Hall effect—with immense potential for transformative applications.

In this talk, I will present our experimental discoveries of two distinct types of correlated quantum materials, each exhibiting unique quantum phases. First, I will show the observation of a correlation-driven magnetic insulating phase in monolayer NbSe2 in its octahedral structural form and demonstrate how heterostructuring with its trigonal prismatic counterpart can lead to new correlated phenomenon. In the second part, I will present our discovery of UOTe, a quasi-2D van der Waals material that exhibits intriguing Kondo lattice physics. Through quasi-particle interference imaging, we achieved the first observation of an unconventional d-wave Kondo effect. This finding provides fresh insights into the half-century-old Kondo problem and highlights the potential of reduced-dimensional systems in uncovering novel correlated quantum phenomena. Finally, I will discuss how these discoveries open pathways for advancements in quantum materials, with potential applications in addressing societal challenges such as clean energy and quantum computing.

Bio: Mengke Liu received her Ph.D. in Physics from the University of Texas at Austin in 2022, focusing on molecular beam epitaxy synthesis and scanning tunneling microscopy characterization of atomic-thin quantum materials. She is currently a Harvard Quantum Initiative Postdoctoral Fellow in the Department of Physics at Harvard University, where she seeks to integrate quasi-particle interference imaging with transport measurements to elucidate emergent correlated topological phenomena in f-electron systems at reduced dimensionality.