2023/09/18 by Kevin He, He, Kevin, Ming Yuan +11 · 1 citation
Engineering · Physics and Astronomy · #Atomic and Subatomic Physics Research #Electromagnetic Simulation and Numerical Methods #FOS: Physical sciences #Quantum Physics (quant-ph) #Quantum and electron transport phenomena #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2309.10145
openalex publication_date 2023/09/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Advancements in quantum system lifetimes and control have enabled the creation of increasingly complex quantum states, such as those on multiple bosonic cavity modes. When characterizing these states, traditional tomography scales exponentially in both computational and experimental measurement requirement, which becomes prohibitive as the state size increases. Here, we implement a state reconstruction method whose sampling requirement instead scales polynomially with subspace size, and thus mode number, for states that can be expressed within such a subspace. We demonstrate this improved scaling with Wigner tomography of multimode entangled W states of up to 4 modes on a 3D circuit quantum electrodynamics (cQED) system. This approach performs similarly in efficiency to existing matrix inversion methods for 2 modes, and demonstrates a noticeable improvement for 3 and 4 modes, with even greater theoretical gains at higher mode numbers.