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Mon November 26, 2012
Dr. Daniel Lidar, University of Southern California – Diamonds and Quantum Computing
In today’s Academic Minute, Dr. Daniel Lidar of the University of Southern California explains why diamonds may be the key to quantum computing.
Daniel Lidar is a professor of chemistry and electrical engineering at the University of Southern California. His research is focused on various aspects of quantum information theory, including quantum algorithms, the theory of open quantum systems, quantum phase transitions and entanglement. He holds a Ph.D. from the Hebrew University of Jerusalem.
Dr. Daniel Lidar – Diamonds and Quantum Computing
In quantum computing, we replace traditional ones and zeroes with quantum bits, or qubits. Taking advantage of the amazing nature of quantum mechanics, qubits can represent a one AND a zero at the same time. This property is called superposition.
Qubits also rely on entanglement, a property that Einstein referred to as “spooky action at a distance.” Entanglement allows particles that have been separated by space to still affect one another. Together, superposition and entanglement may some day allow quantum computers to perform certain calculations faster than traditional computers.
So, you might be wondering, “Will I be checking my email on a quantum computer some day?”
The answer is, probably not. At this point, we believe that the real promise of quantum computers lies in their potential to perform certain specialized calculations, such as random list searches, more rapidly than is in principle possible on their classical counterparts. Essentially, superposition allows quantum computers to search through all the possibilities at once, and entanglement creates stronger-than-classical correlations between potentially correct answers.
However, there is a problem: quantum computers are difficult to build on a large scale since they fall victim to decoherence, which you can think of as the noise that knocks qubits out of superposition.
To address this, my colleagues and I worked out and built a design for a prototype quantum computer in a diamond, using subatomic particles inside the diamond as our qubits. Our design is advantageous because it can work at room temperature, whereas other solid-state designs of quantum computers require temperatures that are even colder than in outer space. Another unique design feature is that by using microwave pulses we were able to protect the system against decoherence.
Our system represents just one possible direction for quantum computers to go. We hope that it will pave the way to bigger and faster systems in the future that may soon rival traditional computers.