Doppler-induced tunable and shape-preserving frequency conversion of microwave wave packets

Quantum Physics [Submitted on 12 Mar 2026] Doppler-induced tunable and shape-preserving frequency conversion of microwave wave packets Felix Ahrens, Enrico Bogoni, Renato Mezzena, Andrea Vinante, Nicolò Crescini, Alessandro Irace, Andrea Giachero, Gianluca Rastelli, Iacopo Carusotto, Federica Mantegazzini In superconducting electronics, the ability to control the frequency of microwave wave packets is crucial for several applications, such as the operation of superconducting quantum processors and the readout of superconducting sensors. We introduce a new approach to microwave frequency conversion harnessing a dynamic Doppler effect induced by a propagating front separating regions of different phase velocities. Employing a high-kinetic-inductance superconducting transmission line in a travelling-wave geometry, we were able to implement frequency shifts of microwave wave packets at 500 MHz and 4 GHz of up to 3.7 % while fully preserving their temporal shape. In contrast to conventional methods based on frequency-mixing, our Doppler-induced frequency-conversion method avoids spurious mixing products, is continuously tunable by a quasi-dc current amplitude, and allows to imprint arbitrary patterns on the instantaneous frequency profile of temporally long wave packets. By engineering transmission lines that allow for larger phase-velocity changes and/or by cascading multiple Doppler-induced frequency conversions, an unlimited amount of frequency shifting is in principle attainable. These features demonstrate the potential of our frequency-conversion technique as a promising tool for advanced control of microwave wave packets for different quantum applications. Subjects: Quantum Physics (quant-ph); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Optics (physics.optics) Cite as: arXiv:2603.12436 [quant-ph]   (or arXiv:2603.12436v1 [quant-ph] for this version)   https://doi.org/10.48550/arXiv.2603.12436 Focus to learn more Submission history From: Felix Ahrens [view email] [v1] Thu, 12 Mar 2026 20:34:41 UTC (8,382 KB) Access Paper: HTML (experimental) view license Current browse context: quant-ph < prev   |   next > new | recent | 2026-03 Change to browse by: cond-mat cond-mat.mes-hall physics physics.optics References & Citations INSPIRE HEP NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)