New type of optical quantum computers

Rare earth ions doped mixed crystals for fast quantum computers with optical frequency qubits

Scientists at the Institute of Physics of the University of Tartu, Estonia have found a way to develop optical quantum computers of a new type, based on the discovery of Rare Earth Ions (REIs) that have certain characteristics and can act as qubits.

The micro-crystals have been synthesized on the basis of mixed optical fluoride crystal matrices doped with erbium, praseodymium and some other ions of rare earth elements.

So they have studied the possibility of using these mixed crystals highly doped with REIs as physical systems for creating fast quantum computers. They found that they might achieve a sampling time of 10-9s and a long decoherence time of the qubits.

Researchers have started building a pilot prototype of quantum computer based on the new method. (

The results of this research have been published in Optics Communications.

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