Ground states of linear rotor chains via the density matrix renormalization group

TL;DR

This paper uses the density matrix renormalization group to analyze ground states of linear rotor chains, revealing a phase transition and advancing methods for studying rotational spectra in nanomolecular assemblies.

Contribution

It demonstrates the application of DMRG to interacting molecular rotors, providing evidence of phase transition and proposing new approaches for spectral analysis.

Findings

Evidence of phase transition via diverging entanglement entropy

Successful computation of ground states for chains up to 50 rotors

Introduction of methods for rotational spectra analysis

Abstract

In recent years, experimental techniques have enabled the creation of endofullerene peapod nanomolecular assemblies. It was previously suggested that the rotor model resulting from the placement of dipolar linear rotors in one-dimensional lattices at low temperature has a transition between ordered and disordered phases. We use the density matrix renormalization group (DMRG) to compute ground states of chains of up to 50 rotors and provide further evidence of the phase transition in the form of a diverging entanglement entropy. We also propose two methods and present some first steps towards rotational spectra of such nanomolecular assemblies using DMRG. The present work showcases the power of DMRG in this new context of interacting molecular rotors and opens the door to the study of fundamental questions regarding criticality in systems with continuous degrees of freedom.