Riechert H, Annabi S, Peugeot A, Duprez H, Hantute M, Watanabe K, Taniguchi T, Arrighi E, Griesmar J, Pillet J-D, Bretheau L
Laboratoire de Physique de la Matière Condensée, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Palaiseau, France.
Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Physique, Lyon, France.
Nat Commun. 2025 Aug 5;16(1):7197. doi: 10.1038/s41467-025-62283-y.
Gate-tunable transmon qubits are based on quantum conductors used as weak links within hybrid Josephson junctions. These gatemons have been implemented in just a handful of systems, all relying on extended conductors, namely epitaxial semiconductors or exfoliated graphene. Here we present the coherent control of a gatemon based on a single molecule, a one-dimensional carbon nanotube, which is integrated into a circuit quantum electrodynamics architecture. The measured qubit spectrum can be tuned with a gate voltage and reflects the quantum dot behavior of the nanotube. Our ultraclean integration, using a hexagonal boron nitride substrate, results in record coherence times of 200 ns for carbon nanotube-based qubits. Furthermore, we investigate its decoherence mechanisms, thus revealing a strong gate dependence and identifying charge noise as a limiting factor. On top of positioning carbon nanotubes as contenders for future quantum technologies, our work paves the way for studying microscopic fermionic processes in low-dimensional quantum conductors.
栅极可调谐跨导量子比特基于用作混合约瑟夫森结中弱链接的量子导体。这些门控量子比特仅在少数几个系统中得以实现，所有这些系统都依赖于外延半导体或剥离石墨烯等扩展导体。在此，我们展示了基于单个分子（即一维碳纳米管）的门控量子比特的相干控制，该碳纳米管被集成到电路量子电动力学架构中。所测量的量子比特频谱可以通过栅极电压进行调谐，并反映了纳米管的量子点行为。我们使用六方氮化硼衬底进行的超清洁集成，使得基于碳纳米管量子比特的相干时间达到了创纪录的200纳秒。此外，我们研究了其退相干机制，从而揭示了对栅极的强烈依赖性，并确定电荷噪声是一个限制因素。除了将碳纳米管定位为未来量子技术的有力竞争者之外，我们的工作还为研究低维量子导体中的微观费米子过程铺平了道路。
