Adsorption by Design

Strain dependence of the potential interaction of adsorbed adatoms on deformed two-dimensional materials offers exciting opportunities to study exotic superfluid phases. I will study how adsorbed phases can be manipulated via mechanical or chemical strain. Calculations in the continuum description using random phase approximation for ${}^4$He at long distances from uniaxially strained graphene can be matched using a new parameterization process. Effective models mirror the close distance physics found using density functional theory, where the adsorption potential minima is pushed to higher distances above the deformed graphene sheet. The enticing possibility of an anisotropic superfluid emerges as strain causes channels in the potential well to open between adsorption sites allowing adatoms to spatially delocalize. Other strain geometries could lead to even more quantum phase transitions. The tuning of the adsorption properties of two-dimensional materials paves the way to answering unsolved questions in quantum materials. Could engineered strain geometries provide a tractable approach to a theoretical description of the elusive two-dimensional supersolid phase (recently proposed) for the helium monolayer? Preliminary results using large scale quantum Monte Carlo simulations indicate interesting behavior in the appropriate regime.