Does Quantum Computing Have a Big But?

Yes, it does. Now understand, quantum computing’s big but is not a big butt. However, the problem ‘it’ has could be influenced more so by a big butt. All kidding aside, this is a well done piece discussing quantum measurements and decoherence; generally, the largest challenge to quantum computing at present. Recommend reading from the source. Because Quantum is Coming. Qubit.

Decoherence Is a Problem for Quantum Computing, But …

Excerpts and salient points ~

+  It seems that quantum computing is becoming more and more advanced by the day. The qubits are getting cleaner, the gates are getting better, and the algorithms are getting more complex. It is apparently only a matter of time before quantum computing becomes a staple technology. However, a major hurtle remains that will require immense efforts to overcome: decoherence.

But the point of this essay is not to belittle quantum computing. It is to highlight another application of quantum mechanics—one that exploits rather than laments a quantum state’s extreme sensitivity to its environment. This is the field of quantum measurement.

+  Quantum computers promise exponential speedup in solving certain types of problems by using quantum principles like superposition and entanglement, but the use of quantum states also leaves the quantum computer much more vulnerable to errors than a classical computer would be. These errors arise from decoherence, a process in which the environment interacts with the qubits, uncontrollably changing their quantum states and causing information stored by the quantum computer to be lost.

+  Decoherence could come from many aspects of the environment: changing magnetic and electric fields, radiation from warm objects nearby, or cross talk between qubits. Quantum scientists have their work cut out for them in wrangling all of these potential sources of decoherence.

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Source:  Scientific American.  Katherine McCormick,  Decoherence Is a Problem for Quantum Computing, But ……

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