As resonantly interacting trimers of the type AAB are progressively squeezed from $D=3$ to $D=2$, unatomic states emerge. We calculated the contacts from the high-momentum tail of the single-particle densities. The sharp increase in the contacts serves as a signature of the transition between the Efimov and unatomic regimes, characterized by the emergence of continuous scale invariance when the system reaches a critical dimension $D_c$. This continuous scale invariance starts to dominate the behavior of the system at the dimension $\overline{D}<D_c$, below which the trimers' momentum-distribution tails exhibit a power-law behavior signaling the unatomic regime. To illustrate our findings, we studied compounds with the forms ${}^7\mathrm{Li}\text{−}{}^{23}\mathrm{Na}_2$, ${}^7\mathrm{Li}\text{−}{}^{87}\mathrm{Rb}_2$, and ${}^7\mathrm{Li}\text{−}{}^{133}\mathrm{Cs}_2$. The increase in the trimers' mass imbalance reduces the interval between $D_c$ and $\overline{D}$. The emergence of unatomic states can be experimentally verified by observing the two-body contact parameter, which is a quantity directly related to the thermodynamic properties of the gas.

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• Efimov states
• Few-body systems
• Trapped atoms