June 24, 2022
Quantum

Traditional computers are particularly good at two things: storing numbers in memory and processing those numbers using simple mathematical operations. Quantum computers use quantum bits, or qubits, to store information. Qubits, like Schrödinger’s cat (which would not have had the same impact if he had selected an inanimate thing), maybe in two separate states of information at the same time.

Quantum computers utilize quantum processors instead of integrated circuits and transistors, which utilize basic particles like neutrons, electrons, and/or atoms. The following are two of the most “crazy and amazing” qualities of these particles:

  • For starters, they are “linked” to other particles that get entangled with them after some kind of contact. When one particle’s spin is detected in the “up” state, the second particle, even though it is extremely far away, will be in the opposite “down” state very instantaneously (i.e., quicker than the speed of light).
  • Second, they exist in a superposition of states before any measurement, implying that large collections of entangled particles (if they existed in the brain) may function in an “orchestrated” or coordinated fashion across great distances. An electron, for example, might be at two distinct energy levels at the same moment or spinning up and down. When they’re measured, however, they’ll be at a given energy level or spin direction, which we refer to as “collapsing” to a specific state. We assign a definite “1” or “0” to a bit while utilizing traditional processors. We may assign “1” to the spin-down state and “0” to the spin-up state of an electron in a quantum processor. However, it will be “1” and “0” at the same time until we measure the state, much as a spinning coin is neither “heads” nor “tails” when spinning. As a result, a single quantum bit, or “qubit,” may represent both “1” and “0” at the same time, unlike a traditional processor’s “bit,” which can only represent “1” or “0” at any one moment. The bit is binary and point-like, but the qubit is “space-like” and “fuzzy,” allowing for more data to be processed in parallel thanks to the superpositions characteristic. At any one moment, a “bit” represents either a 1 or a 0, but a “qubit” may represent both at the same time.

The “1s” and “0s” may be attributed to a variety of physical properties of elementary particles. The spin-up or spin-down states of an atom’s nucleus, the varying energy levels of electrons in an atom, or even the orientation of the plane of polarization of light particles or photons may all be used as examples.

  • Using Phosphorus Atoms for Quantum Computing

The first operational quantum bit was constructed in 2013 by a research team led by Australian engineers from the University of New South Wales (UNSW), based on the spin of the nucleus of a single phosphorus atom inside a protective bed of non-magnetic silicon atoms with zero spins. They achieved record-high precision in recording and reading quantum information using nuclear spin in ground-breaking research published in the journal Nature.

Because the nucleus of a phosphorus atom has a very weak magnetic field and has the lowest spin number of 12 (which implies it is less susceptible to electric and magnetic fields), it is almost impervious to magnetic noise and electrical interference from the surroundings. The surrounding bed of zero-spin silicon atoms further “shields” it from noise. As a consequence, the nuclear spin has a longer coherence time, allowing information to be held for longer periods, resulting in substantially improved precision.

“The nucleus of the phosphorus atom possesses a nuclear spin, which, because of its low susceptibility to noise in the environment, might serve as an ideal memory storage qubit.”

Andrew Zurak provides an update on the work of the UNSW team.

Another team (this time a Dutch-American partnership) employed the nuclear spins of phosphorus atoms in quantum computing in 2014 to reach an even higher precision of 99.99 percent and a longer coherence duration of more than 35 seconds.

  • In our Heads, Quantum Computers?

So, how does any of this relate to our brains? There are various situations in quantum biology where quantum processing has been speculated; for example, evidence exists that birds use quantum processes in their retinas to navigate around the world and that photosynthesis is more effective when long-lived coherent quantum states are achieved. Quantum processing is also thought to be required for the human sense of smell and some components of human eyesight. As a result, it’s unsurprising that we’d hunt for quantum processing in the human brain.

Roger Penrose, a renowned physicist, and Stuart Hammeroff, an anesthesiologist, developed one of the earliest popular ideas. They theorized that quantum processing may be taking place in neuron microtubules. 6 Most scientists were doubtful, however, since the brain was thought to be a warm, damp, and noisy environment in which quantum coherence, which happens only in highly isolated situations and at extremely low temperatures, would be difficult to produce. Penrose and Hammeroff have yet to respond to this critique of their theory convincingly. However, discoveries in extending coherence periods have been made, and research teams all around the globe are attempting to prolong coherence times at room temperatures with some success. 7,8 As a result, the Penrose-Hammeroff hypothesis is currently a work in progress.

  • Fisher’s Revolutionary Concepts

In 2015, physicist Matthew Fisher of the University of California proposed a concept in which nuclear spins in phosphorus atoms may be used as qubits. This model is similar to the one mentioned in the preceding section in that it was created in a laboratory context; the difference is that it was applied to the human brain, which contains a lot of phosphorus.

“Are we, rather than merely brilliant robots creating and constructing quantum computers, quantum computers ourselves?” — Matthew Fisher (Matthew Fisher) is

Fisher has convincingly demonstrated that the spins of phosphorus nuclei can be sufficiently isolated (by the protective cloud of electrons surrounding it and the protective shield of a bed of zero spin atoms) and less “distracted” by quantum noise due to its weak magnetic field (due to its low spin number), allowing quantum coherence to be preserved. (This fact has been validated and confirmed by the laboratory investigations detailed in the preceding section, as well as the experimental findings.) The nuclei of phosphorus atoms would be adequately separated in an environment such as the brain, where electric fields abound.

Pyrophosphate is a chemical molecule that initiates the process in the cell. It’s made up of two phosphates bound together, each containing a phosphorus atom surrounded by zero-spin oxygen atoms (a similar situation as that of the laboratory study discussed above, where the phosphorus atom was nestled inside silicon atoms with zero spin). The phosphates’ spins get entangled as a result of their interaction. One of the resultant configurations is a zero-spin state of maximal entanglement, known as a “singlet.” The entangled phosphates are subsequently broken apart by enzymes into two free phosphate ions, which remain entangled as they drift away. As demonstrated below, these entangled phosphates interact individually with calcium ions and oxygen atoms to form Posner molecules.

These clusters give extra “shielding” to the entangled pairs from outside interference, allowing them to retain coherence across great distances in the brain for significantly longer periods. When Fisher calculated the coherence time for these molecules, he discovered that it was a whopping 105 seconds – a whole day.

  • So, what’s next?

Although Fisher does not seem to layout what occurs next in any detail – which is critical if we are to comprehend the whole picture – this author will attempt to do so. The phosphorus atoms’ entangled nuclei (inside Posner molecules) would be spread out across a large region of the brain. They’d remain in a superposed form for a while, existing as waves, until collapsing. The electrons in the atom react as the atom collapses. The chemical characteristics of atoms are determined by electrons. As a consequence of the collapse, the chemical characteristics of the phosphorus atoms change, causing a chain reaction that sends a cascade of neurotransmitters into the synapses of neurons. The sequence of electrochemical signals is then combined to generate a perception, which is subsequently interpreted depending on the person’s life experiences.

This answers a long-standing topic that has perplexed experts in the field of neuroscience: How does the brain combine information from different sections of the brain to generate a unified perception? A simultaneous collapse of the nuclear spins of entangled phosphorus atoms in distinct layers and sections of the brain, known as “Fisher’s mechanism” (a name used by this author), might be the solution.

  • Limitations

The most apparent drawback is that Fisher’s theories have yet to be thoroughly verified, even though certain features (such as the longer coherence time of phosphorus atoms) have previously been proven in the laboratory. There are, however, intentions to do so. The first step will be to see whether Posner molecules can be found in extracellular fluids and if they can get entangled. Fisher recommends that this be tested in the lab by producing chemical processes that entangle phosphorus nuclear spins, then pouring the solution into two test tubes and checking for quantum correlations in the light that is emitted.

Fisher’s mechanism, according to Roger Penrose, can only assist to explain long-term memory, but it may not be adequate to explain consciousness.

Although most scientists are doubtful, he feels that the Penrose-Hammeroff formulation of microtubules, which he claims are heavier than nuclei, offers a more robust explanation for this goal. If Posner molecules (containing entangled particles) are discovered in these microtubules, both the Fisher and Penrose-Hammeroff theories will be somewhat correct. (After all, who doesn’t appreciate a happy ending?)

Conclusion

Quantum computing using isolated and shielded phosphorus atoms has been shown in the lab to provide very precise results and extended coherence durations. So, can quantum computing be carried out by the human brain? What if the nuclear spins of phosphorus atoms are used as qubits?