Impact of nuclear vibrations on van der Waals and Casimir interactions at zero and finite temperature

Abstract

Van der Waals interactions in atomistic systems depend strongly on temperature, vibrational effects, and dimensionality.

From quantum to continuum mechanics in the delamination of atomically-thin layers from substrates

“…We also point out that long-range atomic deformations (lying in the infrared frequency region) can efficiently interact via the electromagnetic field with the quickly oscillating plasmonic modes 42,43 . In fact, while each of these collective charge oscillation modes lies in the ultraviolet-frequency region, the integral over plasmonic frequency shifts is situated in the infrared range.…”

“…Thermal effects were not considered in this work, but we speculate that finite temperature should in fact increase the adhesive stress in the presence of MBD vdW interactions. In fact, infrared vibrations of organic matter are amplified upon increasing the temperature 42,43 , and this suggests that electronic delocalization increases concomitantly. It would also be interesting to go to multilayer structures and study the mode mixity dependence of adhesive properties and fracture toughness 44 .…”

Mechanical relations between conductive and radiative heat transfer

“…14,15,23,[35][36][37] Thus motivated, we use this section to present a method for unifying both forms of heat transfer in both of these scenarios. This method is based on the retarded many-body (RMB) framework of mesoscale fluctuational EM, [61][62][63] allowing for accurate modeling of fluctuational EM phenomena, including RHT, in atom-scale systems.…”

“…Strictly speaking, the matrices −ω 2 M eα and −ω 2 M Iα should respectively be replaced by − i ωB eα − ω 2 M eα and − i ωB Iα −ω 2 M Iα in order to account for nonzero dissipation, though the dissipation matrices B eα and B Iα may be taken to be infinitesimal; also, once again, the diagonal blocks K Iαα entering Ẑ(0) α should actually include the effects of couplings to nuclear oscillators in other bodies as are present in the offdiagonal blocks K Iαβ for all β = α. With details explained in, 61,63 the RMB oscillator matrix parameters Q eα , M eα , M Iα , K eα , and K Iαα (the latter initially excluding couplings to nuclear oscillators in other bodies) along with the equilibrium atomic positions are all computed using density functional theory (DFT) for each body in isolation, while the matrices B eα and B Iα are assigned phenomenological values. These 2 × 2 block matrices can then be used in place of Ẑ(0) α and ∆ Ẑαβ in the formula for two components with general couplings (10) to find the combined heat transfer including PCHT and RHT: the couplings among valence electronic and nuclear DOFs through EM fields means that PCHT and RHT contributions are not separable, but in fact affect each other.…”

“…In particular, we consider a model system consisting of collinear atomically thin wires, and show that the resulting net heat transfer power does not simply follow from the sum of the individual radiative and conductive contributions, and may in fact fall below either or both of these contributions. Such an illustration is made possible by an extension of the retarded many-body framework of mesoscale fluctuational EM, [61][62][63] which can account for atomscale features of material response. Concluding remarks are given in Section VI.…”