Eliminating Intermediate Measurements using Pseudorandom Generators

  title={Eliminating Intermediate Measurements using Pseudorandom Generators},
  author={Uma Girish and Ran Raz},
  journal={Electron. Colloquium Comput. Complex.},
  • Uma Girish, R. Raz
  • Published 22 June 2021
  • Computer Science
  • Electron. Colloquium Comput. Complex.
We show that quantum algorithms of time $T$ and space $S\ge \log T$ with intermediate measurements can be simulated by quantum algorithms of time $T \cdot \mathrm{poly}(S)$ and space $O(S\cdot \log T )$ without intermediate measurements. The best simulations prior to this work required either $\Omega(T)$ space (by the deferred measurement principle) or $\mathrm{poly}(2^S)$ time [FR21, GRZ21]. Our result is thus a time-efficient and space-efficient simulation of algorithms with intermediate… 

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