• Father Christmas may use 'quantum tunnelling' to get in and out of our homes at Christmas
• He may also have mastered quantum interference and be employing quantum computing to help him meet his annual global delivery target

A researcher at the University of Warwick is challenging the theory that ‘Santa got stuck up the chimney’ by suggesting that he uses ‘quantum tunnelling’ to get himself in and out of our homes.

Dr George Knee, a theoretical physicist, suggests Father Christmas is not bound by the usual every-day laws of physics as we know them and instead employs quantum techniques to help him complete his seemingly impossible global delivery target.

Dr Knee said: “For Santa to achieve his annual mission, it need not be that he operates outside of the laws of physics — just that he operates outside of the laws of ‘classical’ physics.

“Take the issue of getting through the chimney. It is well known that Old Saint Nick is perhaps a little too fond of the mince pies. The narrow cross-section of a typical chimney therefore poses a bit of a challenge, because it is narrower than Santa’s belly. In classical physics the repulsive forces of the edges of the chimney would present a difficult situation.

“But according to quantum physics, the atoms in Santa’s body have an uncertain position – a sort of fuzziness that can slosh around like a liquid. Although it sounds absurd, it is perfectly possible for the uncertainty of Santa’s body to flow directly through otherwise difficult gaps. This means that, in theory, Quantum Santa could simply pop out into the fireplace. This also answers the modern day problem of how Father Christmas reaches you if you don’t have a chimney – he simply uses quantum tunnelling to slide under the door, or through the cat flap.”

Classical physics can be thought of as the physics of common sense, where objects follow a continuous path through space and time and cannot move through hard barriers. Quantum physics on the other hand is far stranger. It is the physics that works at the very smallest scales. It governs the world of atoms, molecules and photons where ‘barriers’ are no longer a problem.

Dr Knee is part of a research group at the University of Warwick that is actively pursuing further insight into quantum effects in biology, as well as in the devices and technology of tomorrow.

Over the past century, scientists have been working to understand quantum physics and to isolate, control and amplify quantum effects up towards bigger scales. There is a lot of theoretical work that shows the potential power of quantum technology and scientists are moving onto practical demonstrations. Relatively large objects can now be placed into quantum states, including artificial objects such as superconducting circuits.

Quantum computers are on the way – small prototypes already exist with large scale devices following in the coming years. So could Santa already have this technology?

Dr Knee said: “It’s not just getting down the chimney that poses a problem for Santa. If you also consider the intensive route-planning and list-checking he must perform, the conventional computing power of a PC or laptop, or perhaps a smartphone or tablet kept in the sleigh, may not be able to search through a database containing a few billion names in time for the quick delivery he needs. And since we know from the song ‘Santa Claus is Coming to Town’ that he checks the list twice, we need to double that time.

“A quantum computer that runs at the same clock speed would have the job done much faster. What’s more, quantum computer scientists discovered that this advantage would be even more important as the database grows. Quantum computers operate on the very same concept of a 'fuzziness' where all the different possible answers can slosh around inside the computer and ‘interfere’ until the correct solution is found.”

This ‘Quantum interference’ can be compared to ripples on the surface of a calm lake. The interplay of the motions introduced by a pair of stones dropped into the lake can result in beautiful patterns, where a peak meets with another peak or a trough – building up the height of the ripple or cancelling it out completely. Quantum technologists aim to become masterful at controlling quantum interference effects, to produce devices with desirable properties such as superfast computers, secure communications or high precision sensors for medical imaging or gravitational wave detection.

Dr Knee added: “The idea that Santa may already possess this kind of technology is not so radical. Some quantum physicists believe that parts of the natural world have already evolved to exploit quantum interference. For example, the principles of quantum mechanics may explain how plants can efficiently transfer and convert energy from the sun during photosynthesis and a quantum mechanism has been suggested to operate in the eye of the European Robin to allow it to accurately perceive the Earth’s magnetic field to help it navigate.”

Contact:

Andrea Cullis

Media relations manager

DD: 02476 528050

M: 07825 314874

E: a dot cullis at warwick dot ac dot uk