# Cosmin Andrei

Cosmin is a senior majoring in Physics with certificates in Applied Mathematics and Applications of Computing. His research is about quasiparticle-induced... Read more about Cosmin Andrei

Youqi is a senior majoring in Electrical Engineering with certificates in Engineering Physics and Applications of Computing. She explores ways to tune... Read more about Youqi Gang

Inci is a second year undergraduate student at Princeton University from Istanbul, Turkey. She works on characterizing qubits with embedded qubit control... Read more about Inci Karaaslan

Hoang is a senior in Electrical Engineering at Princeton with a certificate in Engineering Physics. He explores novel qubit species with better encoding scheme... Read more about Hoang Le

L. Stefanazzi, et al., “The QICK (Quantum Instrumentation Control Kit): Readout and control for qubits and detectors,” arXivv, 2021. Publisher's Version

C. S. Chiu, A. N. Carroll, N. Regnault, and A. A. Houck, “Line-graph-lattice crystal structures of stoichiometric materials,” arXiv, 2021. Publisher's VersionAbstract

The origin of many quantum-material phenomena is intimately related to the presence of flat electronic bands. In quantum simulation, such bands have been realized through line-graph lattices, a class of lattices known to exhibit flat bands. Based on that work, we conduct a high-throughput screening for line-graph lattices among the crystalline structures of the Materials Flatband Database and report on new candidates for line-graph materials and lattice models. In particular, we find materials with line-graph-lattice structures beyond the two most commonly known examples, the kagomé and pyrochlore lattices. We also identify materials which may exhibit flat topological bands. Finally, we examine the various line-graph lattices detected and highlight those with gapped flat bands and those most frequently represented among this set of materials. With the identification of real stoichiometric materials and theoretical lattice geometries, the results of this work may inform future studies of flat-band many-body physics in both condensed matter experiment and theory.

A. Petrescu, et al., “Accurate methods for the analysis of strong-drive effects in parametric gates,” arXiv, 2021.

D. - S. Ma, et al., “Spin-Orbit-Induced Topological Flat Bands in Line and Split Graphs of Bipartite Lattices,” Physical Review Letters, vol. 125, pp. 266403, 2020. Publisher's Version

C. S. Chiu, D. - S. Ma, Z. - D. Song, B. A. Bernevig, and A. A. Houck, “Fragile topology in line-graph lattices with two, three, or four gapped flat bands,” Physical Review Research, vol. 2, pp. 043414, 2020. Publisher's VersionAbstract

The geometric properties of a lattice can have profound consequences on its band spectrum. For example, symmetry constraints and geometric frustration can give rise to topologicially nontrivial and dispersionless bands, respectively. Line-graph lattices are a perfect example of both of these features: Their lowest energy bands are perfectly flat, and here we develop a formalism to connect some of their geometric properties with the presence or absence of fragile topology in their flat bands. This theoretical work will enable experimental studies of fragile topology in several types of line-graph lattices, most naturally suited to superconducting circuits.