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arXiv · 2505.24549

Strongly driven transmon as an incoherent noise source

Linda Greggio·Rémi Robin·Mazyar Mirrahimi·Alexandru Petrescu
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Abstract

Under strong drives, which are becoming necessary for fast high-fidelity operations, transmons can be structurally unstable. Due to chaotic effects, the computational manifold is no longer well separated from the remainder of the spectrum, which correlates with enhanced offset-charge sensitivity and destructive effects in readout. We show here that these detrimental effects can further propagate to other degrees of freedom, for example to neighboring qubits in a multi-qubit system. Specifically, a coherently driven transmon can act as a source of incoherent noise to another circuit element coupled to it. By using a full quantum model and a semiclassical analysis, we perform the noise spectroscopy of the driven transmon coupled to a spectator two-level system (TLS), and we show that, in a certain limit, the interaction with the driven transmon can be modeled as a stochastic diffusive process driving the TLS.

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Linda Greggio, Rémi Robin, Mazyar Mirrahimi, Alexandru Petrescu. 2025-05-30. Strongly driven transmon as an incoherent noise source. https://arxiv.org/abs/2505.24549

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