7 July 2025

Yujie Liu and Philip Thomas win the MCQST PhD Awards 2024

The MCQST PhD Award honors the best PhD theses in quantum science and technology selected from the MCQST community. The prize highlights and recognizes excellence in research at an early career stage, and aims to encourage awardees to pursue a future career in science. MCQST considers outstanding theses in the field of quantum science and technology (grade: summa cum laude) from the disciplines of physics, mathematics, computer science, electrical engineering, material science, and chemistry from both, LMU and TUM.

From the submitted theses, the jury selected and awarded two outstanding works in 2024: "Realization and characterization of topological phases of matter on a digital quantum computer" by Yujie Liu (TUM) and "Photonic graph state generation from individual atoms in an optical cavity”" by Philip Thomas (MPQ). Alongside the recognition of their excellent scientific work and contribution to the MCQST scientific community, the award consist of €2000 each, generously donated by planqc and Qlibri.

The award ceremony took place during the Munich Conference on Quantum Science and Technology 2025 in Kufstein, on 6 June 2025.

Yujie Liu

Realization and characterization of topological phases of matter on a digital quantum computer

UM | Advisor: Frank Pollmann

The discovery of topological order has revised the understanding of quantum matter and provided a cornerstone for quantum error correction. Finding physical realizations of topologically ordered states in experimental settings has been the main challenge en route to utilizing their unconventional properties. In this thesis, we explore the realization and characterization of topological order in synthetic quantum systems. We propose unitary quantum circuits with optimal depth scaling to realize a broad class of topologically ordered states and simulate their quasiparticle excitations. Using this approach, we successfully realize a 31-qubit ground state with Z_2 topological order on Google’s Sycamore quantum processor. Leveraging the concept of isometric tensor networks, we further propose a simple and experimentally accessible route to realizing topological quantum phase transitions. Finally, we investigate the characterization of different quantum phases using efficiently trained quantum convolutional neural networks and techniques from quantum error correction.

"Surrounded by the outstanding students and colleagues of the MCQST community, I am incredibly grateful and honored to have received the MCQST PhD Award. This recognition reinforces my motivation to continue exploring the fascinating world of quantum science.."

After graduating, Yujie is currently conducting postdoctoral research at the Center for Theoretical Physics at MIT. In particular, he is focusing on further exploring the interplay between quantum many-body physics and quantum information science.

Philip Thomas

Photonic graph state generation from individual atoms in an optical cavity

MPQ | Advisor: Gerhard Rempe

Graph states form an important class of multipartite entangled states that serve as key resources in various quantum information processing protocols. In my thesis, I explored the generation of photonic graph states using single atoms coupled to an optical cavity. By emitting single photons sequentially, we realized Greenberger-Horne-Zeilinger (GHZ) states and linear cluster states using a single emitter. In a second step, we employed two individually addressable emitters and a photonic fusion operation to merge smaller graph states into larger and more complex ones.

"Being part of the MCQST community has enriched my PhD journey through countless inspiring and enjoyable encounters. Winning this award is a meaningful reminder of how these experiences have shaped me as a scientist. "

What is next for Philip? Wrapping up some follow-up projects from his thesis while keeping his eyes open for new adventures.

Congratulations to Yujie (Leo) and Philip, and all the best for their future!