Scientists have developed a quantum storage method that could help pave the way for large-scale optical quantum networks.
The new quantum storage system relies on the spin of the nucleus to generate collective oscillations in the form of spin waves, through which several atoms are effectively connected to store information.
Andrei Faraon, a professor of applied physics and electrical engineering at the California Institute of Technology, used a qubit made of ytterbium (Yb, a rare earth element available in lasers) to embed the ion in a transparent crystal of yttrium orthovanadate (YVO4) and manipulate its quantum state through a combination of optical and microwave fields. The team then used qubits from ytterbium to control the spin state of the nuclei of multiple vanadium atoms in the crystal. The findings were published February 16 in the journal Nature.
Image from the journal Nature
"Based on our previous work, a single ytterbium ion is considered an excellent candidate for optical quantum networks," Professor Faraon said, "but we need to connect it to other atoms." We have demonstrated this in this work. ”
The experimental equipment was made at the Kavli Institute of Nanoscience at the California Institute of Technology in the United States, and then tested at low temperatures in Professor Faraon's laboratory.
According to the researchers, this new technique, which utilizes entangled nuclear spins as quantum storage, was inspired by the nuclear magnetic resonance (NMR) approach.
"In order to be able to store quantum information in nuclear spin, we have developed new technologies similar to those used in hospitals," said Joonhee Choi, co-corresponding author of the paper. ”
Each qubit the team measured has an identical register, which means the quantum storage system is capable of storing the same information.
"Being able to replicate and reliably build this technology is the key to success." Andrei Ruskuc, lead author of the paper, said, "In a scientific context, this study gives us an unprecedented understanding of the microscopic interactions between ytterbium qubits and vanadium atoms. ”
The results of this research help lay the foundation for future quantum networks and pave the way for large-scale optical quantum networks.
Quantum computers perform computational functions faster than traditional computers by virtue of the special properties of quantum mechanics, including the superposition property, which allows qubits to store information in the form of both 1s and 0s at the same time.
And like classical computers, engineers want to be able to connect multiple quantum computers, share data and work together, creating a "quantum internet." This will open the door to many applications, including solving huge computing power that a single quantum computer cannot handle, and using quantum cryptography to build unbreakable and secure communication networks.