Is the Human Brain a Quantum Computer?
Quantum computers employ quantum processors that use elementary particles like neutrons, electrons and/or atoms instead of integrated circuits and transistors like classical processors. Two of the very “crazy and magical” properties that these particles have include the next:
• Firstly, they are somehow continuously “connected” to other particles which can be entangled with it after some interaction. For example, when one particle’s spin is measured in the “up” state, one other particle, even though it was very far away, would instantly (i.e. faster compared to the speed of light) take the opposite “down” state. Large collections of entangled particles (if they existed in the brain) could therefore behave in an “orchestrated”or coordinated manner over long distances.
• Secondly, they exist in a superposition of states ahead of any measurement. For example, an electron may take two different energy levels or be spinning up and down at the same time. When measured, however, they’ll be at a particular energy level or spin direction – we say that they have “collapsed” to a certain state. When working with classical processors, we assign a certain “1” or “0” to a bit. In a quantum processor, we could assign “1” to the spin-down state and “0” to the spin-up state of, say, an electron. However, until we measure the state, it will soon be “1” and “0” at the same time frame – just as a spinning coin is neither “heads” nor “tails” if it is spinning. Hence, one quantum bit or “qubit” can represent “1” AND “0” at the same time frame, unlike the classical processor’s “bit” that may only represent “1” OR “0” at a point in time. The bit is binary and point-like nevertheless the qubit is “space-like” and “fuzzy”; this permits much more information to be processed in parallel, benefiting from the property of superpositions. A “bit” represents either a 1 or 0 at a point in time, whereas a “qubit” can represent both at once.1
Various physicist attributes of elementary particles could be assigned the “1s” and “0s “.For example, we can utilize the spin-up or spin-down states of the nucleus of an atom, different energy levels of electrons in an atom, or even the orientation of the plane of polarization of light particles or photons.
Quantum Computing using Phosphorus Atoms
In 2013, a research team led by Australian engineers from the University of New South Wales (UNSW) created the initial working quantum bit based on the spin of the nucleus of a single phosphorus atom in just a protective bed of non-magnetic silicon atoms with zero spin. In a ground-breaking paper in the journal Nature, they reported a record-high accuracy in writing and reading quantum information using the nuclear spin. 2
As the nucleus of a phosphorus atom features a very weak magnetic field and possesses the cheapest spin number of ½ (which means it is less sensitive to electric and magnetic fields), it is nearly immune to magnetic noise or electrical interference from the environment. It is further “shielded” from noise by the surrounding bed of zero-spin silicon atoms. Consequently, the nuclear spin features a longer coherence time enabling information to be stored inside for a lengthier time, which results in a much higher amount of accuracy.
“The core of the phosphorus atom has a nuclear spin, which could act as an excellent memory storage qubit thanks to its very weak sensitivity to the noise contained in the surrounding environment.”
Andrew Zurak, reporting on the UNSW Team’s Work, 3
In 2014, another team (this time a Dutch-US collaboration) used the nuclear spins of phosphorus atoms in quantum computing to reach even greater accuracy of 99.99% and a lengthier coherence time of above 35 seconds. 4,5
Quantum Computer inside our Heads?
So, what does this have regarding our brains? There are many examples in quantum biology where quantum processing has been suspected; for example, there’s evidence that birds utilize quantum processes in their retinas to navigate across the world and that photosynthesis proceeds more efficiently by achieving long-lived coherent quantum states. It has been observed that the human sense of smell and certain aspects of human vision would require quantum processing to occur. So, it is no surprise that people must certanly be looking for quantum processing in the human brain.