# Bloch oscillations in a transmon embedded in a resonant electromagnetic environment

**Authors:** Benjamin Remez, Vladislav D. Kurilovich, Maximilian Rieger, Leonid I. Glazman  
**arXiv:** [2403.04623](https://arxiv.org/abs/2403.04623)  
**Date:** 2024-03-07  
**Summary page:** https://www.summarizepaper.com/en/paper/2403.04623v1/

## Key points

- Study focuses on Josephson junction array transmission lines for strong-coupling circuit electrodynamics in superconducting quantum devices
- Transmission lines offer high impedance environment for robust quantum fluctuations and photon modes
- Observations of charge Bloch oscillations similar to those in crystalline systems when current flows through the junction
- Investigation into behavior of Bloch oscillations in transmon-type qubit connected to high-impedance transmission lines with discrete photon spectra
- Identification of resonances in voltage-current relationship and emitted photon spectrum from Bloch oscillations in transmon system
- Discovery of novel anti-Stokes-like process where photons acquire a Bloch oscillation quantum during interaction with the system
- Manifestation of observable signatures across experimental frequencies ranging from DC to MHz and GHz ranges

## Summary

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In their study, Benjamin Remez, Vladislav D. Kurilovich, Maximilian Rieger, and Leonid I. Glazman delve into the realm of Josephson junction array transmission lines that have been developed to facilitate strong-coupling circuit electrodynamics for various superconducting quantum devices. These transmission lines offer a high impedance environment conducive to robust quantum fluctuations and provide photon modes that enable the probing of quantum devices like small Josephson junctions. The researchers observe charge Bloch oscillations in this high-impedance setting, similar to those found in crystalline systems when current flows through the junction. However, the interaction between Bloch oscillations and environmental photon resonances remains largely unexplored territory. Their investigation focuses on elucidating the behavior of Bloch oscillations in a transmon-type qubit connected to high-impedance transmission lines with discrete photon spectra. Transmons exhibit distinct charge bands that promote Bloch oscillations over Landau-Zener tunneling phenomena. Through their research, the team identifies resonances in both the voltage-current relationship and emitted photon spectrum resulting from Bloch oscillations in the transmon system. They also discover that the transmon can scatter photons inelastically, revealing a novel anti-Stokes-like process where photons acquire a Bloch oscillation quantum during interaction with the system. These findings demonstrate how Bloch oscillations manifest observable signatures across a broad range of experimental frequencies spanning from direct current (DC) to megahertz (MHz) and gigahertz (GHz) ranges. Overall, this comprehensive exploration sheds light on the intricate interplay between charge dynamics within superconducting quantum devices and their surrounding electromagnetic environments, providing valuable insights for future studies and applications in quantum information processing and communication technologies.