2 August 2023

David Gröters and Wun Kwan Yam win the MCQST Master’s Awards 2022

The MCQST Master's Award recognizes two exceptional Master's theses from the MCQST community, each year. This prestigious prize serves to acknowledge and celebrate outstanding research projects undertaken by talented Master's students, with the intention of inspiring and motivating the awardees to pursue successful careers in the field of science. MCQST specifically evaluates remarkable theses submitted by students enrolled in the Master in Quantum Science and Technology program, which is a collaborative effort between TUM and LMU München.

From the submitted theses, the jury selected and awarded two outstanding works in 2022: " Diffraction-limited Imaging and Trapping of Ultracold Ytterbium Atoms in Optical Tweezer Arrays" by David Gröters (LMU München) and "Microwave quantum teleportation over a thermal channel" by Wun Kwan Yam (TU Munich and Walther Meissner Institute). Alongside the recognition of their excellent contribution to the MCQST scientific community, the award consist of €1000 each, generously donated by Zurich Instruments.

The award ceremony took place during the Munich Conference on Quantum Science and Technology 2023 in Sonthofen on Friday, June 23rd, where the Master's Award was celebrated for the first time.

© C. Hohmman / MCQST

David Gröters

Diffraction-limited Imaging and Trapping of Ultracold Ytterbium Atoms in Optical Tweezer Arrays

LMU München | Prof. Monika Aidelsburger

A new path for quantum gas experiments with high resolution is a combination of the advantages of highly uniform optical lattices with the flexibility offered by optical tweezer arrays. Those hybrid tweezer lattices require performant microscope objectives that can simultaneously image individual atoms in the optical lattice and generate diffraction-limited optical tweezers for single-site addressing.

In my thesis I created optical test setups to characterize the imaging performance of our custom made high-resolution objectives as well as to test their tweezer-generation capabilities. Those setups enabled me to map out and analyze both the point-spread-function and 2D optical tweezer arrays in 3D. Finally, we successfully integrated the objectives into the main setup including the trapping and imaging of ultracold ytterbium atoms in a 5x5 optical tweezer array.

During this work, I have also paid much attention on documenting the technical details needed to set up and analyze such optical test measurements in order to prepare future students for this task.

"I feel very grateful and honored to have received this award in such a competitive field of research. It shows me that people will appreciate the time and effort you invest into a project that you are passionate about. I am particularly happy that a thesis was selected that also puts a strong focus on capturing and presenting rather technical knowledge that can be of great use to future students in tackling similar tasks. At the same time I feel privileged to have worked in such a competent and friendly group."

Wun Kwan Yam

© C. Hohmann / MCQST

Microwave Quantum Teleportation Over a Thermal Channel

TU Munich & Walther Meißner Institute | Prof. Rudolf Gross

Quantum communication exploits non-classical correlations to achieve efficient and unconditionally secure exchange of information. One promising approach to quantum communication is by utilizing propagating quantum microwave states. This is because the microwave frequency matches that of superconducting quantum processors, thereby paving the way toward distributed quantum computing. Furthermore, many modern communication and computation tasks operate in the microwave regime, hence propagating quantum microwaves can interface well with the current infrastructure.

Quantum teleportation is an outstanding quantum communication protocol that enables the unconditionally secure transfer of unknown quantum states without directly sending them. For this thesis, we study the continuous-variable implementation of quantum teleportation using propagating quantum microwave states. We investigate the resilience of quantum teleportation against realistic imperfections, namely ambient thermal noise in the communication channels and experimentally limited operating parameters. As a result, we show that microwave quantum teleportation is robust against noise from a thermal feedforward channel and can facilitate secure communication under realistic application scenarios. Finally, we construct a 6.5-meter-long cryogenic link that connects two dilution refrigerators and experimentally demonstrate microwave quantum teleportation between two spatially-separated cryostats. Our system then serves as a prototype quantum local area network for future quantum microwave experiments.

"I am grateful for the recognition by the MCQST Master’s Award and for the support of everyone at the Walther-Meißner-Institute where I completed my thesis. Studying in the vibrant MCQST community let me explore a wide range of possibilities in quantum science and technology. As I delve deeper into science with a doctorate at the Walther-Meißner-Institute, I hope to contribute to quantum communication research and bring the quantum internet closer to reality."

Congratulations to David and Wun Kwan, and all the best for their future!