7 research outputs found
Local measures of fluctuations in inhomogeneous liquids: Statistical mechanics and illustrative applications
We show in detail how three one-body fluctuation profiles, namely the local
compressibility, the local thermal susceptibility, and the reduced density, can
be obtained from a statistical mechanical many-body description of classical
particle-based systems. We present several different and equivalent routes to
the definition of each fluctuation profile, facilitating their explicit
numerical calculation in inhomogeneous equilibrium systems. This underlying
framework is used for the derivation of further properties such as hard wall
contact theorems and novel types of inhomogeneous one-body Ornstein-Zernike
equations. The practical accessibility of all three fluctuation profiles is
exemplified by grand canonical Monte Carlo simulations that we present for hard
sphere, Gaussian core and Lennard-Jones fluids in confinement.Comment: 17 pages, 8 figure
Enhanced colloidal transport in twisted magnetic patterns
Bilayers of two-dimensional materials twisted at specific angles can exhibit
exceptional properties such as the occurrence of unconventional
superconductivity in twisted graphene. We demonstrate here that novel phenomena
in twisted materials emerges also in particle-based classical systems. We study
the transport of magnetic colloidal particles driven by a drift force and
located between two twisted periodic magnetic patterns with either hexagonal or
square symmetry. The magnetic potential generated by patterns twisted at
specific magic angles develops flat channels, which increase the mobility of
the colloidal particles compared to that in single patterns. We characterize
the effect of the temperature and that of the magnitude of the drift force on
the colloidal mobility. The transport is more enhanced in square than in
hexagonal twisted patterns. Our work extends twistronics to classical soft
matter systems with potential applications to lab-on-a-chip devices
Simultaneous and independent topological control of identical microparticles in non-periodic energy landscapes
Colloidal transport in twisted lattices of optical tweezers
We simulate the transport of colloidal particles driven by a static and
homogeneous drift force, and subject to the optical potential created by two
lattices of optical tweezers. The lattices of optical tweezers are parallel to
each other, shifted, and rotated by a twist angle. Due to a negative
interference between the potential of the two lattices, flat channels appear in
the total optical potential. At specific twist angles, known as magic-angles,
the flat channels percolate the entire system and the colloidal particles can
then be transported using a weak external drift force. We characterize the
transport in both square and hexagonal lattices of twisted optical tweezer