Quantum Decoherence Timescales for Ionic Superposition States in Ion Channels

TL;DR

This study re-evaluates quantum decoherence times in ion channels, specifically the KcsA selectivity filter, finding they are significantly longer than previous estimates, but still too short for brain quantum processing.

Contribution

It introduces a detailed numerical analysis of decoherence times in ion channels, focusing on the KcsA selectivity filter, improving upon Tegmark's simplified estimates.

Findings

Decoherence times are in the order of picoseconds.

These times are 10-100 million times longer than Tegmark's estimates.

Decoherence times are insufficient for cognitive quantum processing but may affect ion trace recording.

Abstract

There are many controversial and challenging discussions about quantum effects in microscopic structures in neurons of the human brain. The challenge is mainly because of quick decoherence of quantum states due to hot, wet and noisy environment of the brain which forbids long life coherence for brain processing. Despite these critical discussions, there are only a few number of published papers about numerical aspects of decoherence in neurons. Perhaps the most important issue is offered by Max Tegmark who has calculated decoherence times for the systems of "ions" and "microtubules" in neurons of the brain. In fact, Tegmark did not consider ion channels which are responsible for ions displacement through the membrane and are the building blocks of electrical membrane signals in the nervous system. Here, we would like to re-investigate decoherence times for ionic superposition states by using the data obtained via molecular dynamics simulations. Our main approach is according to what Tegmark has used before. In fact, Tegmark didn't consider the ion channel structure and his estimates are only simple approximations. In this paper, we focus on the small nano-scale part of KcsA ion channels which is called "selectivity filter" and has a key role in the operation of an ion channel. Our results for superposition states of potassium ions indicate that decoherence times are in the order of picoseconds which are 10-100 million times bigger than the order calculated by Tegmark. This decoherence time is still not enough for cognitive processing in the brain, however it can be adequate for quantum states of cooled ions in the filter to leave their quantum traces on the filter and action potentials.