Fig. 2: Experimental system and scheme.
a Adapted with permission from ref. 32. Copyrighted by the American Physical Society. a Schematic of the multimode 3D cQED system with rectangular flute-style storage and readout cavities that both couple to a transmon circuit. Experimental drives are input through a drive pin on the readout cavity, or through a drive pin directly on the storage cavity. b Wigner tomography pulse sequence. Initial cavity displacements and a final generalized multimode parity measurement implement the tomography, while optional conditional π pulses are used to target specific modes and take the transmon portion of their joint transmon-cavity states to \(\left\vert f\right\rangle\) and out of the qubit subspace in the DEMESST approach (see Supplementary Note 5). An additional angle ϕ is applied between the π/2 pulses of the parity measurement to rotate the generalized Wigner function onto the real axis. c Cavity displacement plots for the OLI (orange, above) and DEMESST (purple, below) sampling methods. The OLI has ring features corresponding to measurement of all Fock states up to a cutoff, while DEMESST has points more densely located in the phase space based on the basis state being measured.
