Entangled tale

Conal E. Murray

Subir Sachdev A

inquantio

• A study published on arXiv conducted an unprecedented experiment by inducing a highly resilient multicellular organism, a tardigrade, into a state of suspended animation (cryptobiosis) and placing it directly on a superconducting qubit circuit in an extreme vacuum at millikelvin (mK) temperatures. • The researchers claim that quantum entanglement was formed between the tardigrade and the qubit system, evidenced by changes in the resonance frequency and coupling with a second qubit. • The study confirmed that the tardigrade miraculously revived to an active state upon returning to room temperature and atmospheric pressure after exposure to extreme quantum experimental conditions (sub 10 mK, 6×10^{-6} mbar), pioneering the exploration of the extreme limits where a multicellular organism can survive while integrated with quantum hardware. [Quantum Biology Society] While quantum systems generally require cold, controlled environments, living organisms exist in hot, wet conditions, leading to the assumption that the two systems are inherently incompatible. However, an unconventional attempt to directly couple a multicellular organism with quantum hardware has been reported in the academic community, sparking fierce debate and opening new frontiers in quantum biology. The paper, titled "Entanglement between superconducting qubits and a tardigrade," released on the preprint repository arXiv, details the results of experimentally modeling the interaction and quantum entanglement formation between a highly resilient tardigrade and superconducting qubits. A multinational research team, including K. S. Lee and R. Dumke from Nanyang Technological University and N. Møbjerg from the University of Copenhagen, led this experiment. ■ Extreme Integration of a Living Organism and Quantum Hardware The research team desiccated an adult tardigrade (R. varicornatus) collected in Denmark to induce a state of cryptobiosis (the "tun" state) and placed it between the capacitor plates of a superconducting transmon qubit (Qubit B). The system was then cooled to sub-10 millikelvin (mK) temperatures and an extreme vacuum of 6×10^{-6} mbar. In this state, the tardigrade is placed in perfect stasis, essentially suspending all chemical metabolic processes. ■ Evidence of Quantum Entanglement: Resonance Frequency Shift and State Tomography The maximum resonance frequency of Qubit B, where the tardigrade was placed, shifted down by 8 MHz, which the researchers interpreted as an interaction driven by the tardigrade's dielectric properties. Furthermore, the researchers conducted an experiment to entangle this Qubit B-tardigrade coupled system with a second qubit (Qubit A). After reconstructing the system's density matrix via quantum state tomography, it showed a high fidelity of 82% with the expected entangled state. Based on this data, the team claimed that the tardigrade was in a state of quantum entanglement with the other qubits within the tripartite system (Qubit A - Qubit B - Tardigrade). ■ Miraculous Revival After Extreme Exposure Most surprisingly, even after prolonged exposure to these extreme quantum experimental conditions, the tardigrade miraculously revived to an active metabolic state in liquid water upon returning to atmospheric pressure and room temperature. According to the paper, the tardigrade remained at sub 10 mK temperatures for 420 hours. This sets a new record for the extreme conditions under which a complex multicellular organism can survive, demonstrating that the cryptobiotic state perfectly suspends the organism's chemical activity enough to withstand quantum experiments. ■ New Debates and Possibilities in Quantum Biology This study has sparked an intense debate within the physics community over whether a living organism can truly be entangled with a quantum system. Some scholars strongly object, arguing that the tardigrade merely acted as a dielectric material passively influencing the electric field of the qubit circuit rather than directly participating in entanglement, making it difficult to view this as true biological quantum entanglement. Nevertheless, this experiment is a pioneering case demonstrating that an entire living organism can be physically coupled to quantum hardware and subsequently maintain its biological functions. It is evaluated as having empirically surpassed the concept of complementarity in living organisms proposed by Niels Bohr. It undeniably presents an exciting new path toward developing hybrid systems composed of living matter and quantum bits in the future.

Vlatko Vedral

We provide a quantum model for the recent experiment coupling a tardigrade to superconducting qubits. A number of different perspectives are discussed with the emphasis placed on quantum entanglement between different subsystems involved in the description.

Mahn‐Soo Choi, Christoph Bruder, Daniel Loss

Shaomin Liu, Lin Chen, Mengfan Liang