Quantum ‘Kisses’ Change the Color of Air
The movement of electrons across tiny distances between metals has the power to change the colour of the gap. Nanophotonics researchers discovered that spaces smaller than a nanometre between metals undergo observable colour changes thanks to the movement of electrons in the surrounding area — meaning the scientists could see quantum mechanical processes in action.
A variety of sub-nanometre distances between nano-sized gold balls lit by white light were analyzed in the study with the light in the gap initially reddening as the distance decreased below one nanometre. The colour then shifted towards the blue end of the spectrum after the point at which electrons could use quantum tunnelling to jump across the space between metals without them actually coming into contact (below 0.35 nanometres). The results of the study contribute valuable data to the field of nanoplasmonic device engineering — the creation of tiny technologies involving plasmonic systems.