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Title: What limits mechanical cat-state coherence as mass grows?
Plain: A 16-microgram vibrating crystal has been put into a cat state, a superposition of two distinct motions. The question is whether its decay is fully explained by known noise, or whether something extra appears at larger mass.
Precise: Mechanical resonator of effective mass $m_{\mathrm{eff}}$ in a cat state |alpha> + |-alpha>. Measure the cat decoherence rate $\Gamma_{\mathrm{cat}}$ versus $\mid\alpha\mid^2$ and $m_{\mathrm{eff}}$, and compare with the bath model $\Gamma_{\mathrm{cat}} = 2 \mid\alpha\mid^2 \Gamma_{\mathrm{m}} (2 n_{\mathrm{th}} + 1)$, with $\Gamma_{\mathrm{m}}$ the mechanical energy damping rate and $n_{\mathrm{th}}$ the thermal phonon number, plus two-level-system defect noise. Answer: whether all decoherence is accounted for, and any excess as a function of mass.
Settled by: Systematic Wigner-function tomography of cats across masses and separations with independently measured bath parameters.
Kind: phenomenon
Answer type: mechanism
References: (empty)
Literature status: open
Status note: Cat states of a 16-microgram oscillator were reported in 2023 (Bild et al., Science).
Posed since: (empty)