Image: Ho Chi Minh City/Flickr
How’s this for a technology dream? Energy transported over distances with no need for conductors/carriors. Electricity (for example) goes “in” at some centralized power generation/storage source and comes “out” wherever, with no need for anything in between. So: off-the-grid living not because you’re a solar panel or windmill dynamo, but because “grids” are obsolete. In this dream, electricity has become teleportable, and a new paper posted to the arVix preprint server suggests a way this might be realized.
First devised by IBM's Charles Bennett in 1992, energy teleportation isn’t exactly a new idea. It’s an implication of the principle of quantum entanglement, in which the state of one particle or even atom can be “sent” over potentially a very long distance instantaneously (and very, very securely). How this might result in actual energy being transmitted remained something of a blank until 2008, when researcher Masahiro Hotta, author of the new paper, described a method by which energy isn’t sent directly, but instead is sent via a quantum channel as information that might allow the recipient to “harvest” energy from the surprisingly energetic quantum foam that makes up the absolute vacuum state of the universe.
Recall that if you took absolutely everything out of a cube of space—every single atom and particle—the laws of quantum mechanics say that new, temporary particles would bubble out of the pure emptiness. They would disappear quickly but nonetheless be real enough to be useful. It just takes information to achieve that utility, and measurements have costs in energy. It's that measurement energy that's being sent: the sender makes a measurement on a vacuum state, which requires energy, and sends it along a quantum channel, at the other end of which a recipient receives the results of the measurement.
In effect, our recipient is receiving the energy used to make the initial measurement (in the form of the measurement). Put differently, making a measurement on empty space adds energy to it and if that space happens to be entangled with another one, the second space will experience a negative energy density. An energy transmission has occured.
The possibility of harvesting energy from the vacuum via some sort of remote quantum linkup is the result of the fact that nearby particles in a field are very often entangled with each other. In terms of information, if the sender and receiver are close by, the sender can make measurements on one end that might help the recipient harvest energy on the other (translating to positive and negative additions to the vacuum energies of the two ends). Granted it sounds nothing like our transmission dream described above, but the net effect is of transmitting energy, even if it’s as information.
The catch with Hotta’s initial scheme is that both parties would have to be close together. His revision to the energy transmission idea involves “squeezing” the vacuum states in between the energy sender and receiver. A piece in Physics World explains:
The researchers propose that such squeezed states could be generated in the laboratory by suddenly expanding the length of the edge path travelled by electrons in a quantum Hall state. The quantum Hall effect is seen in thin semiconductors–essentially 2D sheets–that are exposed to a strong magnetic field. Electrons in a quantum Hall state flow unimpeded in one direction along the edge of the semiconductor and provide a "quantum correlation channel" in which entanglement occurs. Hotta says he is currently working with team member Go Yusa to create such a system in the lab.
If it all sounds intensely theoretical, well, it is. Hotta and his team are only now at the point of actual experimentation and, even then, it’s unlikely we’ll be talking about “useful” amounts of energy for a long time. It’s still fun to think about: the gridless grid.