Scientists have so far managed to allow atoms or molecules to be in the so-called superposition state of two positions at the same time, realizing Schrödinger's cat effect. In a new study, scientists at the Swiss Federal Institute of Technology in Zurich (ETH) put a tiny crystal weighing 16 micrograms (billions of times the mass of an atom or molecule) into a superposition of two oscillating states, creating the most powerful crystal yet. Heavy Schrödinger's cat. The research, published in the journal Science on the 20th, is expected to lead to larger and more robust qubits and be used to detect gravitational waves or dark matter.
Scientists have created the heaviest Schrödinger's cat ever, which can be alive (top) and dead at the same time (bottom). Image source: ETH Zurich
Schrödinger's cat is a thought experiment proposed by the famous Austrian physicist Edwin Schrödinger: a cat is kept in an airtight container containing a small amount of radium and cyanide.
The decay of radium has a probability. If the radium decays, the mechanism will be triggered to smash the bottle containing cyanide, and the cat will die; if the radium does not decay, the cat will survive. According to the theory of quantum mechanics, since the radioactive radium is in a superposition of decay and non-decay states, the cat is in a superposition of dead/alive states. This dead and alive cat is the so-called Schrödinger's cat.
The researchers succeeded in creating a so-called Schrödinger's cat using an oscillating crystal, in which the oscillating crystal represents the cat and a superconducting circuit represents the qubits. The link between the qubit and the cat is not the counter and the poison, but a layer of piezoelectric material, a crystal that changes shape when oscillated, creating an electric field. The electric field can be coupled with the electric field of the qubit, and the superposition state of the qubit can be transferred to the crystal, so that the crystal can oscillate up and down at the same time. This crystal weighing 16 micrograms in the superposition state has thus become the heaviest Schrödinger's so far. cat.
The research team hopes to further improve the mass limit of Schrödinger's cat to better understand why quantum effects go undetected in the real macroscopic world. In addition, the latest research promises to lead to larger, more robust qubits. Moreover, massive objects in a superposition state are extremely sensitive to external noise, and can also be used to accurately measure small disturbances such as gravitational waves or detect dark matter.
