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QUBITWIRE 100

Andrew M. Childs

Professor of Computer Science

University of Maryland

University of Maryland
United States · work baseIdentification checked 2026-09-19
WHY INCLUDED

Childs develops quantum algorithms based on walks and simulation, showing how quantum dynamics can produce provable computational advantages and even implement universal quantum computation.

University of MarylandarXiv / ACM STOCarXiv / Physical Review Letters

Childs’s research treats quantum evolution as an algorithm-design resource. His collaborative quantum-walk result constructed a black-box problem with an exponential separation from classical computation, providing a different mechanism from familiar Fourier-transform algorithms. His later universality result showed that suitably designed graphs can encode arbitrary quantum computation in a walk. Together, these works explain both why quantum dynamics can be useful and how expressive a simple-looking model can become. Their importance lies in explicit constructions and resource analysis, rather than an assertion that ordinary random walks or every physical system deliver an advantage.

University of MarylandarXiv / ACM STOCarXiv / Physical Review Letters

Defining contributions

Work, in context
  1. 2003

    A quantum-walk exponential separation

    Childs and five coauthors constructed a graph-traversal problem in an oracle model that a continuous-time quantum walk solves exponentially faster than classical algorithms can. The model and input-access assumptions are essential to interpreting this theoretical speedup.

    Coauthored theoretical result by Andrew M. Childs, Richard Cleve, Enrico Deotto, Edward Farhi, Sam Gutmann and Daniel A. Spielman.

    Source-supported recordarXiv / ACM STOC
  2. 2009

    Showing quantum walks can be universal

    Childs proved that universal quantum computation can be implemented through a walk on a suitably constructed low-degree graph. Quantum gates are encoded through scattering, showing that a constrained dynamical model can still express general quantum computation.

    Sole-author universality theorem by Andrew M. Childs.

    Source-supported recordarXiv / Physical Review Letters

Follow the evidence

3 sources

Primary papers, institutional records and attributed announcements. Each source supports the claims linked above.

  • University of MarylandInstitutional researcher homepage

    Andrew M. Childs

    Current CS/UMIACS professorship, QuICS affiliation and research interests.

    Checked 2026-09-19
  • arXiv / ACM STOCResearch paper

    Exponential algorithmic speedup by quantum walk

    Childs and collaborators; oracle-model separation; preprint 2002, STOC publication 2003.

    Published 2003 · Checked 2026-09-19
  • arXiv / Physical Review LettersResearch paper

    Universal computation by quantum walk

    Childs authorship and universal construction; 2008 preprint, 2009 journal publication.

    Published 2009 · Checked 2026-09-19
QubitWire editorial · Content edition 2026-09-19.1Independent coverage. Inclusion does not imply endorsement.