University of Arizona Researchers Specialize in Quantum Error Correction, Ensure Proper Calculations
Researchers Work to Ensure Accurate Decoding in Fragile Quantum States
+ Today’s computers are made up of billions of basic building blocks called logic gates. These gates apply different operations to binary information being processed. For example, one of the simplest kinds of gates is a NOT gate, which transforms bits into their opposites by intaking 0s and outputting 1s and vice versa. However, sometimes signal interference and noise cause gates to make mistakes, which leads to incorrect results.
+ Quantum gates perform more versatile and exotic operations than their classical relatives do, but are noisier and more prone to error.
“The biggest advantage of LDPC codes is that they support these kinds of message-passing algorithms, which are fault tolerant,” Vasić said. “In quantum systems, we have to have fault tolerance, because, due to the higher level of noise, quantum gates are orders of magnitude noisier and more unreliable than classical logic gates.”
+ Error correcting codes entangle qubits in a very specific way so that qubits stabilize each other. Vasić’s decoders allow qubits to pass information about one another back and forth. Similar message passing algorithms are used in artificial intelligence. None of the individual bits have a complete knowledge of value of other bits, but together – through message passing – they collectively learn if there are errors and exactly which bits they are located in. This new project focuses on developing a quantum version of such artificial intelligence algorithms.
+ Vasić and several other engineering faculty members are also part of the newly created Center for Quantum Networks, a five-year, $26 million NSF Engineering Research Center led by the University of Arizona. The center, directed by Guha, aims to lay the foundations for the quantum internet, and error correction represents a critical piece of the venture.
+ “This is a missing piece to realize quantum computers and networks,” Vasić said. “These quantum LDPC codes are the next generation of codes that will be used, but we have to develop algorithms to decode efficiently and fault-tolerantly.”
+ With the recent hiring of several new faculty members specializing in quantum engineering, the college and university are positioning themselves at the forefront of this field,” said David W. Hahn, Craig M. Berge dean of the College of Engineering. “We are fortunate to have researchers like Dr. Vasić bring their experience and invaluable expertise to the table.”
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