Reading a Quantum Clock Costs More Energy Than Actually Running One

Quantum technologies—devices that operate according to quantum mechanical principles—promise to bring users some groundbreaking innovations in whichever context they appear. Ironically, the same principles often create complications preventing these supposedly amazing devices from really taking off.

A new study, published on November 14 in Physical Review Letters , further cements this problem by demonstrating another, somewhat unexpected obstacle—the act of measurement itself. For the experiment, physicists constructed a microscopic quantum clock and found that the energy required to read quantum clocks can rise up to a billion times greater than what’s needed to run the clock.

The findings highlight something “often ignored in the literature,” or the cost of observation in quantum me