What limits mechanical cat-state coherence as mass grows? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

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 · changed · core
Revision 1: 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.
Revision 2: Mechanical resonator of effective mass $m_{\mathrm{eff}}$ in a cat state $\left|\alpha\right> + \left|-\alpha\right>$. 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)

Decisions