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Quantum computing without wavefunctions: time-dependent density functional theory for universal quantum computation.

ABSTRACT: We prove that the theorems of TDDFT can be extended to a class of qubit Hamiltonians that are universal for quantum computation. The theorems of TDDFT applied to universal Hamiltonians imply that single-qubit expectation values can be used as the basic variables in quantum computation and information theory, rather than wavefunctions. From a practical standpoint this opens the possibility of approximating observables of interest in quantum computations directly in terms of single-qubit quantities (i.e. as density functionals). Additionally, we also demonstrate that TDDFT provides an exact prescription for simulating universal Hamiltonians with other universal Hamiltonians that have different, and possibly easier-to-realize two-qubit interactions. This establishes the foundations of TDDFT for quantum computation and opens the possibility of developing density functionals for use in quantum algorithms.

SUBMITTER: Tempel DG

PROVIDER: S-EPMC3341739 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

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Quantum computing without wavefunctions: time-dependent density functional theory for universal quantum computation.

Tempel David G DG Aspuru-Guzik Alán A

Scientific reports 20120502

We prove that the theorems of TDDFT can be extended to a class of qubit Hamiltonians that are universal for quantum computation. The theorems of TDDFT applied to universal Hamiltonians imply that single-qubit expectation values can be used as the basic variables in quantum computation and information theory, rather than wavefunctions. From a practical standpoint this opens the possibility of approximating observables of interest in quantum computations directly in terms of single-qubit quantitie ...[more]

PMID: 22553483

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Quantum computing without wavefunctions: time-dependent density functional theory for universal quantum computation.

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Quantum computing without wavefunctions: time-dependent density functional theory for universal quantum computation.

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