Power of One Bit of Quantum Information

  title={Power of One Bit of Quantum Information},
  author={Emanuel Knill and Raymond Laflamme},
  journal={Physical Review Letters},
In standard quantum computation, the initial state is pure and the answer is determined by making a measurement of some of the bits in the computational basis. What can be accomplished if the initial state is a highly mixed state and the answer is determined by measuring the expectation of {sigma}{sub z} on the first bit with bounded sensitivity? This is the situation in high temperature ensemble quantum computation. We show that in this model it is possible to perform interesting physics… 

Computing with highly mixed states

It is shown that unless m∈O(k + log n), oblivious (gate-by-gate) simulation of an ideal m-qubit quantum circuit by an n-qu bit circuit with k clean qubits is impossible, this indicates that there is no avoiding physical initialization of a quantity of qubits proportional to that required by the best ideal quantum circuit.

Are Quantum Computing Models Realistic

The commonly used circuit model of quantum computing leaves out the problems of imprecision in the initial state preparation, particle statistics, and error correction, so the question if a hierarchy of quantum-type computing models exists is speculated.

Computational Complexity of Some Quantum Theories in $1+1$ Dimensions

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Negative quasi-probability as a resource for quantum computation

A central problem in quantum information is to determine the minimal physical resources that are required for quantum computational speed-up and, in particular, for fault-tolerant quantum

Blindness and Verification of Quantum Computation with One Pure Qubit

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Eliminating intermediate measurements in space-bounded Quantum computation

This work exhibits a procedure to eliminate all intermediate measurements that is simultaneously space efficient and time efficient, and shows that the definition of a space-bounded quantum complexity class is robust to allowing or forbidding intermediate measurements.

Quantum computers

The latest developments for each of the leading approaches to quantum computation are described and the major challenges for the future are explained.

Verified Delegated Quantum Computing with One Pure Qubit

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General description of discriminating quantum operations

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Testing integrability with a single bit of quantum information

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Data is reported here to show that a purified particulate preparation from heart muscle which contains all the components of the cytochrome electron transmitter system also contains transhydrogenase, and no reaction whatsoever occurs with TPNH, whether added as such or generated by the glucose-6-phosphate dehydrogenase system.

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