Variable Frequency Pulse Generation from Breathers in Josephson Transmission Lines

TL;DR

This paper presents a novel method to generate variable frequency microwave pulses directly within cryogenic environments using breather dynamics in Josephson transmission lines, improving quantum system control efficiency.

Contribution

It introduces a protocol for in-situ gigahertz pulse generation from breather formations in Josephson lines, eliminating the need for room temperature synthesis and additional resistors.

Findings

Achieves 97% energy efficiency in pulse generation

Generates 15.2 to 21.5 GHz microwave tones

Provides bandwidths from 40 to 365 MHz

Abstract

Single flux quantum technology has the potential to enhance readout and control of superconducting quantum systems due to their low energy consumption, high speed, and cryogenic operating temperatures. Current cryogenic readout and control typically requires microwave pulses of specific frequencies to travel between the room temperature control electronics and the cryogenic setup. Latency in control and readout can be improved by generating pulses within the dilution refrigerator. In this work, we consider a protocol for generating gigahertz frequency microwave tones from trains of DC-centered fluxons and fluxoids in Josephson transmission lines using the dynamics of breather formation, without room temperature synthesis or shunt / bias resistors. Simulations show that pulses with frequencies in the range of 15.2 to 21.5 GHz can be generated with maximal energy efficiency of 97% and bandwidth from 40 to 365 MHz. This protocol can also be used to generate gigahertz frequency Gaussian pulses. We detail metrics relevant to the control and readout of quantum systems such as input power, output power, and footprint.