Physicists break new record for storing a qubit in a memory crystal

As part of the European Quantum Flagship program, scientists managed to increase the duration of qubit storage in a crystal to

20 milliseconds.“This is a world record for quantum memory based on a solid-state system, in this case a crystal. We even managed to reach the 100 millisecond mark with a slight loss of accuracy,” the scientists explain.

UNIGE scientists used crystals dopedcertain rare earth metals (in this case europium). They are able to absorb light and then re-emit it. The crystals were stored at –273.15°C (absolute zero). If I increase even by 10°C the thermal excitation of the crystal destroys the entanglement of the atoms.

The scientists applied a small magnetic field to the crystal.field of 0.001 Tesla and sent intense radio frequencies to the crystal. This affected the europium ions and increased the performance of the storage system by 40 times.

Development of quantum telecommunication systemslong-range is hindered by one limitation. Beyond a few hundred kilometers, the photons are lost and the signal disappears. However, it cannot be copied or amplified, otherwise it will lose the quantum state that guarantees data confidentiality. Therefore, the task of scientists is to find a way to repeat it without change, creating "repeaters" based on quantum memory.

Earlier, in 2015, physicists managed to keepa crystal of a qubit carried by a photon for 0.5 milliseconds. This process allowed the photon to transfer a quantum state to the atoms of the crystal before disappearing. However, this phenomenon did not last long enough to allow the construction of a larger network.

Read more

"James Webb" took the clearest photo of a star in history

Developments of Moscow radiologists on AI became the basis of federal standards

Quantum charging will allow record-breaking fast charging of electric vehicles