Broadband Lamb shift in an engineered quantum system

Tutkimustuotos: Lehtiartikkeli



  • Tokyo Medical and Dental University
  • Helsinki School of Economics
  • RWTH Aachen University
  • National Institute of Standards and Technology
  • VTT Technical Research Centre of Finland


The shift of the energy levels of a quantum system owing to broadband electromagnetic vacuum fluctuations—the Lamb shift—has been central for the development of quantum electrodynamics and for the understanding of atomic spectra 1–6 . Identifying the origin of small energy shifts is still important for engineered quantum systems, in light of the extreme precision required for applications such as quantum computing 7,8 . However, it is challenging to resolve the Lamb shift in its original broadband case in the absence of a tuneable environment. Consequently, previous observations 1–5 , 9 in non-atomic systems are limited to environments comprising narrowband modes 10–12 . Here, we observe a broadband Lamb shift in high-quality superconducting resonators, a scenario also accessing static shifts inaccessible in Lamb’s experiment 1,2 . We measure a continuous change of several megahertz in the fundamental resonator frequency by externally tuning the coupling strength to the engineered broadband environment, which is based on hybrid normal-metal–insulator–superconductor tunnel junctions 13–15 . Our results may lead to improved control of dissipation in high-quality engineered quantum systems and open new possibilities for studying synthetic open quantum matter 16–18 using this hybrid experimental platform.


JulkaisuNature Physics
TilaJulkaistu - kesäkuuta 2019
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

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