Fast Rabbits

So in Korea I was introduced to the concept of a quantum battery by an Australian academic who had trouble explaining how they worked. He was so shifty that I decided I would look into it.

Quantum batteries “work” by taking physical systems, made of atoms or molecules engineered into qubits, and pumping energy into them so they occupy higher-energy states rather than their lowest-energy state.

This is not inherently special, or even quantum. Excitation energy is everywhere. A hot rock has excitation energy. The claimed quantum benefit is that many such tiny units might be able to be charged collectively through coherence or entanglement, potentially increasing charging rates in idealised models. That is, fast charging, mate. We all want that, right?

However, for a superconducting-qubit-style “quantum battery”, the cryogenic and control energy required to maintain and manipulate the relevant quantum states needed to get that fast charging would be around 10^22 times larger (I could have rounded it up to a mole) than the stored excitation energy, depending on assumptions.

That is, for one AAA quantum battery you would need 1 billion trillion normal AAA batteries to run the thing.

Even for academics this is stretching things. I think this is very good evidence that we can safely shut down all Australian university research. They haven’t lost the plot – they can’t even recall that there ever was one.