Quantum Bridge Between Rubidium and Cesium express
A quantum computer is like an orchestra where each musician plays their own part, but all must sound in harmony. Until now, most quantum circuits were built from identical atoms — as if the orchestra consisted only of violins. Now physicists have taught two different elements to work together: rubidium and cesium. They performed an entangling operation between them — a special quantum connection where the state of one atom instantly affects the other, no matter where it is. The operation's accuracy was 97.5% — out of a hundred attempts, only two or three fail.
Why mix different atoms? It turns out this helps solve a long-standing problem: how to check whether a quantum computer has made an error without destroying its fragile state. Usually, any measurement "collapses" the quantum system, like touching a soap bubble. But if one type of atom (cesium) is used for computation and another (rubidium) as a delicate "probe," you can peek into the system without breaking it. This method is called non-destructive measurement, and in the experiment it worked: for groups of two and three atoms, error-checking accuracy was 93% and 86%.
It's like having a tuner in the orchestra who listens to each violin during the performance and quietly adjusts an out-of-tune string without stopping the concert. In quantum computing, errors are inevitable — atoms get knocked off course by the slightest disturbances. Now there's a way to catch such glitches on the fly and fix them without interrupting the computation. The accuracy is far from perfect, but the principle works, and this opens the path to quantum computers that could solve problems beyond the reach of classical machines.
There's still much work ahead: improving operation accuracy and learning to combine hundreds of atoms into a single quantum circuit. But the first bridge between different elements has been built, and the orchestra sounds a bit more confident.
Cesium is used in the world's most accurate atomic clocks: the second is defined by the vibrations of this very element. Rubidium, on the other hand, is found in cheaper, compact clocks used in navigation satellites.
In the TV series "Devs," a quantum computer is built from many different qubits, and the characters struggle with their instability — much like in this work, except in reality it all happens on a table with lasers and a vacuum chamber.