Lieb-Liniger-like model of quantum solvation in CO-(4)HeN clusters.

Area of Science:

• Quantum Chemistry
• Atomic and Molecular Physics
• Condensed Matter Physics

Background:

• Small helium-4 clusters doped with molecules enable the study of quantum solvation.
• A key phenomenon is solvent decoupling and free molecular rotation, indicating microscopic superfluidity.
• The quantum mechanics of this decoupling are poorly understood due to the complexity of the (N+1)-body problem.

Purpose of the Study:

• To investigate the quantum mechanical mechanism of solvent decoupling in helium-4 clusters.
• To explore the transition from a molecular cluster to a quantum solvated molecule.
• To understand the role of cluster size and inter-atomic interactions in quantum solvation.

Main Methods:

• A one-dimensional model of helium-4 atoms on a ring around a rotating CO molecule was studied.
• The Lanczos algorithm was employed to analyze the eigenvalue spectrum.
• The Hamiltonian matrix structure was examined to understand inter-block coupling.

Main Results:

• Substantial solvent decoupling was observed with as few as N=5 helium-4 atoms.
• The Hamiltonian matrix showed increasingly weak solvent-molecule coupling with increasing N.
• A rapid transition to the Lieb-Liniger gas limit was found as N increased.

Conclusions:

• The decoupling mechanism is driven by increasing repulsive interactions between helium atoms as the cluster grows.
• While superfluidity describes the process, a molecular perspective offers complementary insights.
• This research elucidates the quantum mechanism behind the transition in solvated molecular clusters.