Ann: First indication of on-chip qubit control, page-62

Now that I understand what 'room temperature' means and the fact that it is at least 294 degrees (Celsius) above the temperature our friends in China have been able to work with, I believe we may be onto something here. Well, truth be told, my previous post was a bit tongue-in-check, but I think the fact that people took me seriously speaks volumes about how weird this achievement actually is by Archer.

Maybe Archer is closing in on the 'W state', which is an entangled quantum state of three qubits. This is remarkable for representing a specific type of multipartite entanglement and for occurring in several applications in quantum information theory. Particles prepared in this state reproduce the properties of Bell's theorem, which states that no classical theory of local hidden variables can produce the predictions of quantum mechanics.

In other words, we'll be singing when we are winning. All about the W's in this world!

One of the greatest challenges involved with constructing quantum computers is controlling or removing quantum decoherence. This usually means isolating the system from its environment as interactions with the external world cause the system to decohere. However, other sources of decoherence also exist. Examples include the quantum gates, and the lattice vibrations and background thermonuclear spin of the physical system used to implement the qubits. Decoherence is irreversible, as it is effectively non-unitary, and is usually something that should be highly controlled, if not avoided. Decoherence times for candidate systems in particular, the transverse relaxation time T2 (for NMR and MRI technology, also called the dephasing time), typically range between nanoseconds and seconds at low temperature. Currently, some quantum computers require their qubits to be cooled to 20 millikelvins in order to prevent significant decoherence. A 2020 study argues that ionizing radiation such as cosmic rays can nevertheless cause certain systems to decohere within milliseconds.

Room temperature. Not bad.