We propose an autonomous quantum error correction scheme using squeezed cat (SC) code against excitation loss in continuous-variable systems. Through reservoir engineering, we show that a structured dissipation can stabilize a two-component SC while autonomously correcting the errors. The implementation of such dissipation only requires low-order nonlinear couplings among three bosonic modes or between a bosonic mode and a qutrit. While our proposed scheme is device independent, it is readily implementable with current experimental platforms such as superconducting circuits and trapped-ion systems. Compared to the stabilized cat, the stabilized SC has a much lower dominant error rate and a significantly enhanced noise bias. Furthermore, the bias-preserving operations for the SC have much lower error rates. In combination, the stabilized SC leads to substantially better logical performance when concatenating with an outer discrete-variable code. The surface-SC scheme achieves more than one order of magnitude increase in the threshold ratio between the loss rate κ1 and the engineered dissipation rate κ2. Under a practical noise ratio κ1/κ2 = 10−3, the repetition-SC scheme can reach a 10−15 logical error rate even with a small mean excitation number of 4, which already suffices for practically useful quantum algorithms.
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Cross-Layer Control Adaptation for Autonomous System Resilience
The last decade has seen tremendous advances
in the transformation of ubiquitous control, computing and
communication platforms that are anytime, anywhere. These
platforms allow humans to interact with machines through
sensing, control and actuation functions in ways not imaginable a
few decades ago. While robust control techniques aim to maintain
autonomous system performance in the presence of bounded
modeling errors, they are not designed to manage large multiparameter
variations and internal component failures that are
inevitable during lengthy periods of field deployment. To address
the trustworthiness of autonomous systems in the field, we
propose a cross-layer error resilience approach in which errors
are detected and corrected at appropriate levels of the design
(hardware-through software) with the objective of minimizing the
latency of error recovery while maintaining high failure coverage.
At the control processor level, soft errors in the digital control
processor are considered. At the system level, sensor and actuator
failures are analyzed. These impairments define the health of the
system. A methodology for adapting the control procedure of the
autonomous system to compensate for degraded system health is
proposed. It is shown how this methodology can be applied to
simple linear and nonlinear control systems to maintain system
performance in the presence of internal component failures.
Experimental results demonstrate the feasibility of the proposed
methodology.
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- Award ID(s):
- 1723997
- NSF-PAR ID:
- 10098275
- Date Published:
- Journal Name:
- International On-Line Testing Symposium
- Page Range / eLocation ID:
- 261 to 264
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/IOLTS.2018.8474159
