Dynamical decoupling

Dynamical decoupling (DD) is an open-loop quantum control technique employed in quantum computing to suppress decoherence by taking advantage of rapid, time-dependent control modulation. In its simplest form, DD is implemented by periodic sequences of instantaneous control pulses, whose net effect is to approximately average the unwanted system-environment coupling to zero.[1][2] Different schemes exist for designing DD protocols that use realistic bounded-strength control pulses,[3] as well as for achieving high-order error suppression[4]},[5] and for making DD is compatible with quantum gates.[6][7][8]

Periodic repetition of suitable high-order DD sequences may be employed to engineer a ‘stroboscopic saturation’ of qubit coherence, or coherence plateau, that can persist in the presence of realistic noise spectra and experimental control imperfections. This permits device-independent, high-fidelity data storage for computationally useful periods with bounded error probability.[9]

References

  1. Viola, L.; Lloyd, S. (1998). "Dynamical suppression of decoherence in two-state quantum systems". Physical Review A 58 (4): 2733. doi:10.1103/PhysRevA.58.2733.
  2. Viola, L.; Knill, E.; Lloyd, S. (1999). "Dynamical Decoupling of Open Quantum Systems". Physical Review Letters 82 (12): 2417. doi:10.1103/PhysRevLett.82.2417.
  3. Viola, L.; Knill, E. (2003). "Robust Dynamical Decoupling of Quantum Systems with Bounded Controls". Physical Review Letters 90 (3). doi:10.1103/PhysRevLett.90.037901.
  4. Khodjasteh, K.; Lidar, D. (2005). "Fault-Tolerant Quantum Dynamical Decoupling". Physical Review Letters 95 (18). doi:10.1103/PhysRevLett.95.180501.
  5. Uhrig, G. S. (2007). "Keeping a Quantum Bit Alive by Optimized π-Pulse Sequences". Physical Review Letters 98 (10). doi:10.1103/PhysRevLett.98.100504.
  6. Viola, L.; Lloyd, S.; Knill, E. (1999). "Universal Control of Decoupled Quantum Systems". Physical Review Letters 83 (23): 4888. doi:10.1103/PhysRevLett.83.4888.
  7. West, J. R.; Lidar, D. A.; Fong, B. H.; Gyure, M. F. (2010). "High Fidelity Quantum Gates via Dynamical Decoupling". Physical Review Letters 105 (23). doi:10.1103/PhysRevLett.105.230503.
  8. Yang, W.; Wang, Z. Y.; Liu, R. B. (2010). "Preserving qubit coherence by dynamical decoupling". Frontiers of Physics 6: 2. doi:10.1007/s11467-010-0113-8.
  9. Khodjasteh, K.; Sastrawan, J.; Hayes, D.; Green, T. J.; Biercuk, M. J.; Viola, L. (2013). "Designing a practical high-fidelity long-time quantum memory". Nature Communications 4. doi:10.1038/ncomms3045.
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