The intersection of quantum mechanics and biology is a fascinating frontier. Recently, a team of researchers attempted to entangle a tardigrade, a microscopic animal also known as a water bear, with a superconducting qubit. This bold experiment, detailed in a preprint on arXiv, has sparked considerable debate within the scientific community. While the researchers claim they achieved quantum entanglement, others argue their conclusions overreach the actual findings.
The core concept at play is quantum entanglement, where two or more particles become interconnected, sharing properties regardless of the distance separating them. Knowing the state of one entangled particle instantly reveals information about the others. While entanglement occurs naturally, scientists induce it in controlled lab settings to study quantum mechanics. Tardigrades, known for their resilience and ability to enter a state of suspended animation called cryptobiosis, were chosen for this experiment due to their ability to withstand extreme conditions, including the vacuum of space. This cryptobiotic state allows them to survive harsh environments by shedding moisture and reanimating when conditions improve.
The tardigrade species Echiniscus succineus under a microscopeMicroscopic image of the tardigrade species Echiniscus succineus. Image: Wikimedia Commons
The researchers, based in Singapore, Denmark, and Poland, collected Ramazzottius varieornatus tardigrades from a Danish roof gutter and induced cryptobiosis. They then placed individual tardigrades onto a superconducting qubit, a quantum bit capable of representing 0 and 1 simultaneously, unlike classical bits. Observing a shift in the system’s resonance frequency – the frequency at which an object vibrates most strongly – they suggested the tardigrade had coupled with the qubit. Furthermore, they proposed that this combined tardigrade-qubit system became entangled with a second, adjacent qubit on the same silicon chip.
A tardigrade in its active stateA tardigrade in its active state, showcasing its unique morphology. Image: Wikimedia Commons
However, the scientific community has expressed skepticism. Physicist Douglas Natelson argues that the observed frequency shift doesn’t necessarily indicate meaningful entanglement, suggesting the tardigrade’s interaction with the qubit may be no different than the underlying silicon chip’s. Quantum engineer Clarice Aiello points out that the experiment didn’t measure the tardigrade’s properties independent of the qubit, making it difficult to confirm true entanglement versus other classical effects. She emphasizes that quantum biology focuses on the internal quantum dynamics within living organisms, which this experiment didn’t explore.
Simplified diagram of a superconducting qubitSimplified representation of a superconducting qubit, the core component of the experiment. Image: Wikimedia Commons
The research team acknowledges the limitations of their measurements, admitting they couldn’t measure the tardigrade’s system independently. They express intentions to explore this in the future. Entangling a macroscopic object like a tardigrade, significantly larger than atoms or photons typically used in entanglement experiments, would be a groundbreaking achievement. While previous studies hinted at quantum phenomena in photosynthesis and bacteria, demonstrating quantum systems at such a scale remains a considerable challenge.
Entangling a tardigrade with a qubit raises fundamental questions about the interplay between quantum mechanics and biology. While the current findings are debated, the research highlights the exciting possibilities at this scientific intersection. Further investigation and refined experimental techniques are needed to determine whether true quantum entanglement has been achieved and to explore its potential implications.
