Epilogue: Quantum Computing
Vivek S Kale · 2019
The requirements of massive parallelism envisaged in the future are achievable more effectively through quantum computing. In a quantum computer, the atoms are essentially used as processors and memories at the same time. One of the most significant problems in making practical applications of quantum computers is retrieving the results of the computations. Measuring the results of a quantum computation is problematic because interfering in any way with the atoms being used for computation can change their value, collapsing them back into the single state 1 or 0 instead of their coherent superposition of many states. A person, organization, or government with access to a powerful quantum computer could use Peter Shor’s factoring algorithm to break into any encrypted message and recover the supposedly secure information; encryption methods could be made obsolete. Substantial progress in fighting decoherence and other potential error sources will need to be made before robust quantum computers, capable of solving computationally difficult problems, can be built.