Materials Bound by Non-Chemical Forces: External Fields and the Quantum Vacuum

TL;DR

This paper explores materials stabilized by external fields and quantum vacuum effects, highlighting their potential for novel states of matter and applications in nanoscale self-assembly and biological processes.

Contribution

It introduces the concept of materials stabilized by external electric, magnetic, and quantum vacuum forces, and discusses their implications for new states of matter and nanotechnology.

Findings

External fields can stabilize unique material states.

Casimir effect influences biological aggregation processes.

Interplay of forces enables nanoscale self-assembly.

Abstract

We discuss materials which owe their stability to external fields. These include: 1) external electric or magnetic fields, and 2) quantum vacuum fluctuations in these fields induced by suitable boundary conditions (the Casimir effect). Instances of the first case include the floating water bridge and ferrofluids in magnetic fields. An example of the second case is taken from biology where the Casimir effect provides an explanation of the formation of stacked aggregations or "rouleaux" by negatively charged red blood cells. We show how the interplay between electrical and Casimir forces can be used to drive self-assembly of nano-structured materials, and could be generalized both as a probe of Casimir forces and as a means of manufacturing nanoscale structures. Interestingly, all the cases discussed involve the generation of the somewhat exotic negative pressures. We note that very little is known about the phase diagrams of most materials in the presence of external fields other than those represented by the macroscopic scalar quantities of pressure and temperature. Many new and unusual states of matter may yet be undiscovered.