Prof. Dr. Devrim Güçlü
Izmir Institute of Technology
“Quantum Monte Carlo Study of two-dimensional quantum simulators”
Abstract
With recent developments in fabrication of photonic and solid-state based artificial lattice structures, new opportunities emerged regarding quantum simulator applications [1]. In particular, semiconductor based artificial graphene structures [2] and moiré heterobilayers [3] allows the exploration of complex phenomena arising from electron-electron interactions in honeycomb and triangular lattices. In this work, we study electronic and magnetic properties of finite sized artificial lattice structures with honeycomb and triangular symmetry using variational and diffusion Monte Carlo methods which treat electron-electron interactions non-perturbatively. This allows us to investigate the validity of (i) Lieb’s theorems for bipartite lattices [4], (ii) exact diagonalization based prediction of edge depolarization in triangular graphene quantum dots [5] and (iii) Nagaoka ferromagnetism in finite honeycomb lattices [6]. Moreover, in moiré transition metal dichalcogenide heterobilayer structures, we explore the possibility of Wigner crystallization at 1/3 filling and ferromagnetic phase transition at 3/2 filling as predicted by experimental studies [3].
- I. Buluta and F. Nori, “Quantum simulators”, Science 326: 108 (2009). 2. S. Wang et al., “Observation of Dirac bands in artificial graphene in small-period nanopatterned GaAs quantum wells.” Nat. Nanotechnol., 13, no. 1, pp. 29-33 (2017). 3. Y. Xu, S. Liu,D. A. Rhodes, K.Watanabe, T. Taniguchi, J.Hone, V. Elser, K. F.Mak, and J. Shan, Nature 587, 214 (2020) 4. G. Öztarhan, E. B. Kul , E. Okcu , and A. D. Güçlü, “Quantum Monte Carlo study of semiconductor artificial graphene nanostructures.” Physical Review B 108, L161114 (2023). 5. A.D. Güçlü, P. Potasz, O. Voznyy, M. Korkusinski, P. Hawrylak, “Magnetism and correlations in fractionally filled degenerate shells of graphene quantum dots” Phys. Rev. Lett. 103 (24), 246805 (2009) 6. J. P. Dehollain et al., “Nagaoka ferromagnetism observed in a quantum dot plaquette”, Nature volume 579.7800 (2020)
Prof. Dr. Devrim Güçlü received his Ph.D. in Condensed Matter Theory from McGill University, Canada in 2003. He did postdoctoral research at Cornell University and Duke University before joining the Quantum Theory Group at the National Research Council of Canada in 2008 as a research associate. In 2012, he joined the Izmir Institute of Technology, Turkey, where he currently works as a Professor of Physics. His research interests focus on investigation of electronic, optical and magnetic effects in low-dimensional nanostructures using many-body computational techniques such as quantum Monte Carlo and configuration interaction.
Date : November 13, 2024 Wednesday
Time : 15:30
Place : SA-240
All interested are cordially invited.