Strontium ions (blue) confined in a Paul trap
Sum-frequency generation @ 620nm
Linear Paul trap
Reference cavity for qubit laser
Reference cavity for qubit laser
Welcome to the Trapped Ion Quantum Technologies group led by Markus Hennrich. Our group is located at the Department of Physics at Stockholm University and is working on using trapped ions for quantum computation, quantum simulation and quantum sensing applications. In particular, we are one of only two groups worldwide that have realised trapped Rydberg ions - a promising technology for speeding up trapped ion quantum computers.
Excellent news: Our project Open 2D Quantum Simulator (Open-2QS) is funded by a European Research Council (ERC) Synergy Grant - see here. We will be working alongside the groups of Igor Lesanovsky from the University of Tübingen and Ferdinand Schmidt-Kaler from the Johannes Gutenberg University Mainz on this exciting journey.
Our project Open-2QS aims to use quantum simulators with electronically excited ion crystals to explore complex questions in physics, while also shedding light on intricate processes in chemistry, biology, and information processing. It’s an ambitious endeavor, and we’re grateful for the support of the ERC.
We have submitted our manuscript Harry Parke, et al., Phononic bright and dark states: Investigating multi-mode light-matter interactions with a single trapped ion arXiv:2403.07154.
In this work we experimentally investigate a new formalism to describe interference effects, based on collective states which have enhanced or suppressed coupling to a two-level system. We observe the emergence of phononic bright and dark states for both a single phonon and a superposition of coherent states and demonstrate that a view of interference which is based solely on their decomposition in the collective basis is able to intuitively describe their coupling to a single atom.
We have submitted our manuscript Marion Mallweger, Milena Guevara-Bertsch, et al., Motional state analysis of a trapped ion by ultra-narrowband composite pulses, arXiv:2402.10041 .
In this work. we present a method for measuring the motional state of a trapped ion. Our technique uses ultra-narrowband composite pulses on the blue sideband transition to scan through the populations of the different motional states. It is applicable both inside and outside of the Lamb-Dicke regime. For higher phonon numbers especially, the composite pulse sequence can be used as a filter for measuring phonon number ranges.
