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Published on: May 30, 2014
High-order noise filtering in nontrivial quantum logic gates.
Todd Green1, Hermann Uys, Michael J Biercuk
1Centre for Engineered Quantum Systems, School of Physics, The University of Sydney, New South Wales 2006 Australia.
Physical Review Letters
|October 4, 2012
Summary
This study presents a new method to model errors in quantum logic operations caused by classical noise. The effective Hamiltonian theory efficiently calculates error rates for quantum gates, improving quantum computing accuracy.
Area of Science:
- Quantum Computing
- Quantum Information Science
- Theoretical Physics
Background:
- Quantum logic operations are susceptible to errors from time-dependent classical dephasing environments.
- Noncommuting control operations in quantum systems lead to both dephasing and depolarization errors, complicating error rate calculations.
Purpose of the Study:
- To develop an efficient theoretical treatment for modeling classical noise effects on quantum logic operations.
- To provide a general method for calculating ensemble-averaged entanglement fidelity to arbitrary order.
Main Methods:
- Utilized effective Hamiltonian theory to model classical noise impacts on single-bit quantum logic operations.
- Developed a general method to calculate entanglement fidelity using noise filter functions.
- Derived explicit filter functions to fourth order in noise strength for piecewise-constant control sequences.
Main Results:
- The effective Hamiltonian theory efficiently models classical noise effects on arbitrary quantum control sequences.
- Explicit expressions for entanglement fidelity were derived up to fourth order in noise strength.
- Derived filter functions in the weak noise limit demonstrated good agreement with numerical simulations for dynamically corrected gates.
Conclusions:
- The developed treatment provides an efficient and accurate method for understanding and mitigating errors in quantum logic operations.
- This work offers a pathway to improving the performance and reliability of quantum computations by accounting for environmental noise.
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