Terra Quantum, in collaboration with several research institutes, has developed a new superconducting qubit, dubbed the “flowermon”, which is expected to significantly increase coherence times in quantum processors. The flowermon qubit uses atomically thin crystals twisted together to suppress environmental effects on qubit coherence. This development could greatly improve the scalability of superconducting quantum processors. The flowermon is less sensitive to environmental effects, including charge noise and quasiparticle dissipation, which results in an exponential suppression of decoherence. This research could be a major step forward in the development of practical quantum computers.
Introduction to the Flowermon Qubit
In a recent study, scientists from Terra Quantum, in collaboration with other research institutions, have demonstrated a new superconducting qubit, termed the “flowermon” qubit. This new class of superconducting devices utilizes unconventional hybrid materials and is expected to significantly enhance the coherence times in quantum processors. The research paper, titled “Superconducting Qubit Based on Twisted Cuprate Van der Waals Heterostructures,” was published in Physical Review Letters.
The Flowermon Qubit and Its Unique Properties
The flowermon qubit is formed by twisting atomically thin superconducting crystals to a 45-degree angle, creating a special junction that maintains high coherence without the need for highly precise control of fabrication, tuning of the system, or circuit loops susceptible to environmental disturbances. This simpler fabrication and tuning process, coupled with longer coherence times, make the flowermon qubit a promising prototype for a new class of hybrid devices that utilize the benefits of quantum materials and coherent quantum circuits.
Coherence and Its Importance in Quantum Computing
Coherence refers to the ability of a quantum system to maintain a superposition of quantum states over time. This is a crucial aspect of quantum information processing and a key factor in the development of useful quantum computers. Josephson junctions, formed by two superconducting materials separated by a thin barrier, are the foundational building blocks of superconducting quantum computers. However, other qubit types offering high coherence times often rely on multiple junctions in a flux loop, making them vulnerable to noise and fabrication imperfections.
The Flowermon Qubit: A Solution to Noise and Fabrication Imperfections
In contrast, the flowermon is a novel single-junction qubit that inherently protects against these drawbacks, including the exponential suppression of charge noise, providing a robust platform for future quantum devices. The flowermon is created by twisting two flakes of Bi2212, a cuprate high temperature superconductor that preserves nearly perfect superconductivity, to a 45-degree angle to create a flower-like shape of the energy spectrum. This specific angle suppresses single electron pair tunneling across the junction, allowing two-pair tunneling to dominate the junction behavior.
The Future of Quantum Devices with the Flowermon Qubit
The research builds on foundational superconducting technologies that date back to the discovery of superconductivity in 1911. With this new prototype for high-coherence hybrid superconducting quantum systems, the researchers hope to set the foundation for the future of quantum devices based on high temperature superconductors. Future research on the qubit may explore the practical implementation of these schemes to achieve the orders of magnitude improvement in coherence time at scale. The research was funded by the European Union (European Research Council), Deutsche Forschungsgemeischaft, US NSF Grant Awards, and Terra Quantum.
