For the first time, an international team of researchers has used a quantum computer to create artificial life—a simulation of living organisms that scientists can use to understand life at the level of whole populations all the way down to cellular interactions.
With the quantum computer, individual living organisms represented at a microscopic level with superconducting qubits were made to “mate,” interact with their environment, and “die” to model some of the major factors that influence evolution.
The new research, published in Scientific Reports on Thursday, is a breakthrough that may eventually help answer the question of whether the origin of life can be explained by quantum mechanics, a theory of physics that describes the universe in terms of the interactions between subatomic particles.
Modeling quantum artificial life is a new approach to one of the most vexing questions in science: How does life emerge from inert matter, such as the “primordial soup” of organic molecules that once existed on Earth?
Individuals were represented in the model using two qubits. One qubit represented the individual’s genotype, the genetic code behind a certain trait, and the other its phenotype, or the physical expression of that trait.
To model self-replication, the algorithm copied the expectation value (the average of the probabilities of all possible measurements) of the genotype to a new qubit through entanglement, a process that links qubits so that information is instantaneously exchanged between them. To account for mutations, the researchers encoded random qubit rotations into the algorithm that were applied to the genotype qubits.
The algorithm then modeled the interaction between the individual and its environment, which represented aging and eventually death. This was done by taking the new genotype from the self-replicating action in the previous step and transferring it to another qubit via entanglement. The new qubit represented the individual’s phenotype. The lifetime of the individual—that is, how long it takes the information to degrade or dissipate through interaction with the environment—depends on the information coded in this phenotype.
Finally, these individuals interacted with one another. This required four qubits (two genotypes and two phenotypes), but the phenotypes only interacted and exchanged information if they met certain criteria as coded in their genotype qubits.