Ilya Besedin, ETH Zurich, Switzerland
Title: “Realizing Lattice Surgery on Two Distance-Three Repetition Codes with Superconducting Qubits”
Time: Friday, 25.04., 11:15 h
Rudolf Gross received the Werner Heisenberg Medal of the Alexander von Humboldt Foundation in recognition of his special services in promoting international scientific cooperation and as a long-standing member of the Selection Committee for the Humboldt and Friedrich Wilhelm Bessel Research Awards. "It was a very fulfilling task to support the AvH Foundation in granting up to 100 awards every year to internationally leading researchers of all disciplines from abroad in recognition of their academic excellence", Rudolf Gross states. "Promoting international coopoeration will becomes even more important today to fill in trenches caused by politics", he adds.
The German Science foundation (DFG) funds ‘Chiral phonons for spintronics (CHIPS)‘, which is the only physics focused research unit within this funding round. CHIPS wants to understand the physical properties of these chiral phonons in connection with magnetism and spintronics, i.e. in connection with the spin of electrons. How can chiral phonons be generated, transported and recorded? In order to get to the bottom of these questions, the group is looking at time and length scales at the atomic level that have not yet been investigated. This should make it possible to gain new fundamental insights into phonons and potentially identify new spintronic applications. The collaborative effort unites research teams at the University of Konstanz, the University of Augsburg, the Freie Universiät Berlin, the Max-Born-Institut Berlin, the RWTH Aachen, and the Walther-Meißner-Institut.
On April 1st, 2025, Prof. Rudolf Gross retires as Scientific Director of the Walther-Meißner-Institute after shaping the development of the institute for nearly 25 years. During this time, he established WMI as a leading research center in the fields of superconductivity, magnetism, materials science, and quantum technologies, as well as one of the key institutes in the Munich quantum science ecosystem. Today, we celebrate his last official working day with a traditional Weißwurstessen.
Thank you, Rudolf, for everything you have done for the institute!
The toolsets for building quantum computers continue to expand. At WMI, we have leveraged simultaneous parametric interactions to realise Perfect State Transfer between distant superconducting qubits in a chain. Our results reveal that for larger excitation numbers, the phase of the transferred state depends on the number of excitations in the chain. Using this property, we prepare a GHZ state with 88.08% fidelity in a single transfer operation, demonstrating its effectiveness for efficient entanglement generation.
Already in 2010, WMI proposed Planck spectroscopy as an efficient tool for the calibration of cryogenic microwave setups (cf. Mariantoni et al., PRL 105, 133601 (2010)). Now, WMI researchers propose an improved version of Planck spectroscopy, allowing for the in-situ estimation of signal losses in the cryogenic setup used for quantum state tomography of weak microwave signals. With this improved technique they can resolve changes in microwave losses as small as 0.1 dB. Among others, this allows for the more precise characterization of quantum limited amplifiers.
