Dresden 2026 – scientific programme

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O: Fachverband Oberflächenphysik

O 72: 2D Materials beyond graphene: Growth, structure and substrate interaction – Poster (joint session O/TT)

O 72.6: Poster

Wednesday, March 11, 2026, 18:00–20:00, P2

Boosting the Efficiency of Quantum Replica-Exchange Molecular Dynamics — •Jan-Niklas Mohr, Shubham Sharma, and Mariana Rossi — MPI for the Structure and Dynamics of Matter, Hamburg, Germany

Replica exchange molecular dynamics can be combined with path-integral techniques in order to incorporate quantum statistics in the sampled ensembles [1]. However, the efficiency in swapping replicas is decreased to a point that makes simulations extremely inefficient at lower temperatures.

We propose a new acceptance criterion for path-integral replica-exchange molecular dynamics (PI-REMD) that incorporates the path-integral spring term in the Hamiltonian and rescales it consistently. As a result, the acceptance probability is only sensitive to potential-energy differences, and the efficiency of the method is thus increased. Benchmarking on several test systems, including asymmetric double wells and glassy-like potentials, shows that our method outperforms standard PI-REMD in sampling efficiency and exchange frequency. We also show improvements for realistic materials, such as monolayer 1H-TaS₂ [2], where it is paramount to obtain an accurate description of the charge-density-wave phase transition. Our acceptance criterion therefore provides an efficient and reliable tool for studying quantum phase transitions and exploring thermodynamic ensembles under challenging conditions.

[1] Kapil et al., Comput. Phys. Commun. 236, 214-223 (2019).

[2] Schobert et al., SciPost Phys. 16, 046 (2024)

Keywords: Quantum Phase Transitions; Path-Integral Molecular Dynamics; 2D Materials; Replica-Exchange; Charge-Density Waves