Major Progress Made Towards Developing Quantum Computers

Quantum computers will have a significant effect on society when researchers complete developmental advances on them. They will have the ability to improve the design of pharmaceutical drugs, increase the power of artificial intelligence, increase the accuracy of predicting weather patterns, and do other things such as improve the analysis of data.

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A team of physicists from the Harvard-MIT Center for Ultracold Atoms and other universities has developed a special type of quantum computer known as a programmable quantum simulator capable of operating with 256 quantum bits, or “qubits.”

The system marks a major step toward building large-scale quantum machines that could be used to shed light on a host of complex quantum processes and eventually help bring about real-world breakthroughs in material science, communication technologies, finance, and many other fields, overcoming research hurdles that are beyond the capabilities of even the fastest supercomputers today. Qubits are the fundamental building blocks on which quantum computers run and the source of their massive processing power.

“This moves the field into a new domain where no one has ever been to thus far,” said Mikhail Lukin, the George Vasmer Leverett Professor of Physics, co-director of the Harvard Quantum Initiative, and one of the senior authors of the study published today in the journal Nature. “We are entering a completely new part of the quantum world.”

According to Sepehr Ebadi, a physics student in the Graduate School of Arts and Sciences and the study’s lead author, it is the combination of system’s unprecedented size and programmability that puts it at the cutting edge of the race for a quantum computer, which harnesses the mysterious properties of matter at extremely small scales to greatly advance processing power. Under the right circumstances, the increase in qubits means the system can store and process exponentially more information than the classical bits on which standard computers run.

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“Our work is part of a really intense, high-visibility global race to build bigger and better quantum computers,” said Tout Wang, a research associate in physics at Harvard and one of the paper’s authors. “The overall effort [beyond our own] has top academic research institutions involved and major private-sector investment from Google, IBM, Amazon, and many others.”

The researchers are currently working to improve the system by improving laser control over qubits and making the system more programmable. They are also actively exploring how the system can be used for new applications, ranging from probing exotic forms of quantum matter to solving challenging real-world problems that can be naturally encoded on the qubits.

Vital Part for Quantum Computers Invented

Universal quantum computers are still somewhere around a decade or two away from being developed, but they will be significant when they arrive. Important new problems will be solved, but new problems will also be created. Much of the cryptography that the world replies upon today will be rendered ineffective (and will need to be replaced) when faced against quantum computers… For example, the asymmetric RSA regularly used to protect online banking will need to be phased out due to what quantum computers will do to today’s asymmetric ciphers. The symmetric cipher AES-256 will have its strength cut in half when faced against a quantum computer, downgrading it to an adequate but less strong AES-128. This is of course only one example.

A team at the University of Sydney and Microsoft, in collaboration with Stanford University in the US, has miniaturised a component that is essential for the scale-up of quantum computing. The work constitutes the first practical application of a new phase of matter, first discovered in 2006, the so-called topological insulators.

Beyond the familiar phases of matter — solid, liquid, or gas — topological insulators are materials that operate as insulators in the bulk of their structures but have surfaces that act as conductors. Manipulation of these materials provide a pathway to construct the circuitry needed for the interaction between quantum and classical systems, vital for building a practical quantum computer.

Theoretical work underpinning the discovery of this new phase of matter was awarded the 2016 Nobel Prize in Physics.