The principle of quantum superposition allows the system to be prepared with two arbitrary state superpositions. A paradigmous example is the superposition of two coherent states. Superposition of such states is usually referred to as the Schrödinger cat state, but in Irwin Schrodinger’s original thought experiment, a cat-temperature-equal system system is prepared with superposition of two mixed states dominated by classical variation. Physicists at the University of Innsbruck have now managed to create the state of Hot Schrodinger cats with a superconducting microwave resonator.
Yang et al. We generated highly mixed quantum states with different quantum properties. Image credit: Innsbruck University.
SchrödingerCat states are an attractive phenomenon in quantum physics, where quantum objects exist simultaneously in two different states.
In Erwin Schrödinger’s thought experiment, it is a cat living and dead at the same time.
In real experiments, such simultaneity is seen in the positions of atoms and molecules, as well as the vibrations of electromagnetic resonators.
Previously, these analogues to Schrodinger’s thought experiments were first created by cooling quantum objects to their ground state.
In a new study, Dr. Gerhard Kirchumere and his colleagues at Innsbruck University demonstrated that it is indeed possible to create quantum superpositions from thermally excited states.
“Schrodinger also envisioned a living, namely “hot” cat in his thought experiments,” says Dr. Kirchumere, author of the study.
“We wanted to know if these quantum effects could also be produced if they didn’t start from the ‘cold’ ground state. ”
To generate the Schrödinger CAT state, researchers used a transmon Qubit with a microwave resonator.
They have succeeded in creating quantum layers at temperatures up to 1.8 k. This is 60 times the ambient temperature of the cavity.
“Our results show that it is possible to generate highly mixed quantum states with distinct quantum properties,” says Dr. Ian Yang, the first author of the study.
Scientists used two special protocols to create the state of Hot Schrodinger cats.
These protocols have been used previously to produce CAT states starting from the ground state of the system.
“It turns out that the tuned protocol also works at high temperatures and produces clear quantum interference,” said Professor Oriol Romero Isart, co-author of the study.
“This opens up new opportunities for the creation and use of quantum superpositions, for example, in nanomechanical oscillators.
“When I first mentioned our results, many of our colleagues were surprised because we usually think of temperature as a disruption to quantum effects,” says Thomas Agnius, co-author of the study.
“Our measurements confirm that quantum interference can last even at high temperatures.”
The findings could benefit quantum technology development.
“Our work reveals that quantum phenomena can be observed and used in warm, less ideal environments,” Dr. Kirchem said.
“If the system can create the interactions it needs, temperature is ultimately irrelevant.”
a paper The findings were published in the journal Advances in science.
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Ian Yang et al. 2025. Hot Schrodinger cat condition. Advances in science 11 (14); doi:10.1126/sciadv.adr4492
Source: www.sci.news
