Giant vacuum forces via transmission lines

Significance Quantum theory states that at zero temperature and in the absence of any radiation, there still exist fluctuations of the electromagnetic field, the so-called vacuum fluctuations. These fluctuations give rise to the well-known van der Waals (vdW) or Casimir forces between neutral objects, which underlie diverse phenomena in physics and chemistry. We find that these forces can be drastically enhanced for neutral particles near a transmission line (TL), the standard workhorse of electronic signal transmission. The vacuum fluctuations are then confined to propagate along the TL axis, resulting in a giant long-range vdW force. This dramatic effect would have profound implications on vdW and Casimir phenomena and may find novel applications in emerging quantum technologies. Quantum electromagnetic fluctuations induce forces between neutral particles, known as the van der Waals and Casimir interactions. These fundamental forces, mediated by virtual photons from the vacuum, play an important role in basic physics and chemistry and in emerging technologies involving, e.g., microelectromechanical systems or quantum information processing. Here we show that these interactions can be enhanced by many orders of magnitude upon changing the character of the mediating vacuum modes. By considering two polarizable particles in the vicinity of any standard electric transmission line, along which photons can propagate in one dimension, we find a much stronger and longer-range interaction than in free space. This enhancement may have profound implications on many-particle and bulk systems and impact the quantum technologies mentioned above. The predicted giant vacuum force is estimated to be measurable in a coplanar waveguide line.