Sideband thermometry of ion crystals

authored by
Ivan Vybornyi, Laura S. Dreissen, Dominik Kiesenhofer, Helene Hainzer, Matthias Bock, Tuomas Ollikainen, Daniel Vadlejch, Christian F. Roos, Tanja E. Mehlstäubler, Klemens Hammerer

Coulomb crystals of cold trapped ions are a leading platform for the realisation of quantum processors and quantum simulations and, in quantum metrology, for the construction of optical atomic clocks and for fundamental tests of the Standard Model. For these applications, it is not only essential to cool the ion crystal in all its degrees of freedom down to the quantum ground state, but also to be able to determine its temperature with a high accuracy. However, when a large ground-state cooled crystal is interrogated for thermometry, complex many-body interactions take place, making it challenging to accurately estimate the temperature with established techniques. In this work we present a new thermometry method tailored for ion crystals. The method is applicable to all normal modes of motion and does not suffer from a computational bottleneck when applied to large ion crystals. We test the temperature estimate with two experiments, namely with a 1D linear chain of 4 ions and a 2D crystal of 19 ions and verify the results, where possible, using other methods. The results show that the new method is an accurate and efficient tool for thermometry of ion crystals.

Institute of Theoretical Physics
Institute of Quantum Optics
CRC 1227 Designed Quantum States of Matter (DQ-mat)
External Organisation(s)
National Metrology Institute of Germany (PTB)
Vrije Universiteit Amsterdam
Österreichische Akademie der Wissenschaften
University of Innsbruck
PRX Quantum
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Electronic, Optical and Magnetic Materials, Physics and Astronomy(all), Applied Mathematics, Electrical and Electronic Engineering, Computer Science(all), Mathematical Physics
Electronic version(s) (Access: Open)