Dartmouth Events

Abstract: While quantum technologies promise unique computational advantages, quantum systems are inherently susceptible to interactions with their environment, making them noisy, and limiting their utility. For realistic noise having both a white and a non-Markovian component, a combination of quantum error correction and dynamical decoupling (DD) has been proposed to reach fault-tolerance. While existing error analyses have shown this approach to be promising, they do not fully account for the fact that the environment is quantum-mechanical as well, and its state can evolve non-trivially in response to the control that is enacted on the system. Explicitly accounting for the environment's evolution, we show that the fidelity of a DD-protected identity gate can be negatively affected by the history of the applied DD-controls, challenging the traditional notion of a constant error-per-gate. An approach using high-order DD to mitigate this is discussed, and its implications for fault-tolerant quantum error correction.

Hosted by Professor Lorenza Viola

Email Physics.Department@dartmouth.edu for passcde