Building Quantum Computers with Cold Atoms: Mikhail Lukin on Error Correction and Rydberg States
Five lessons from the lone scientist beating IBM and Google at quantum computing.
We'd like to share with you some highlights from our conversation with Mikhail Lukin, Professor of Physics at Harvard University and pioneer in quantum computing with cold atoms.
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I. The Fundamental Challenge of Quantum Computing
All objects around us are made of quantum particles that could theoretically exist in multiple states simultaneously. However, these large quantum superpositions never exist naturally.
Building a quantum computer requires creating and maintaining these delicate superposition states - something that has never been done at scale before.
II. The Birth of Error Correction
In the late 1990s, many experts believed quantum computers could never be built due to their inherent fragility. The solution came in the form of quantum error correction - using redundancy to protect quantum information.
By spreading quantum information across many physical qubits, errors can be detected and corrected without destroying the quantum state.
III. A Living Quantum Processor
Lukin's team made a breakthrough by using cold atoms trapped in optical tweezers as qubits. Unlike traditional computer chips with fixed architectures, these atoms can be physically moved around.
This allows them to reconfigure the processor's connectivity in real-time, like a "living organism."
IV. From Stopping Light to Quantum Computing
The journey began with experiments on "stopping light" using electromagnetically induced transparency. This led to work on Rydberg states - highly excited atomic states where electrons orbit far from the nucleus.
These Rydberg states enable controlled interactions between atoms, forming the basis for quantum logic operations.
V. The Path Forward
While significant challenges remain, Lukin sees a clear path to systems with hundreds of logical qubits using current techniques. Going beyond that to thousands of logical qubits will require new innovations.
The key is viewing quantum computing not just as a technological challenge, but as a fundamental scientific problem.
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