Biased Estimator Channels for Classical Shadows

Understand

Extracting classical information from quantum systems is of fundamental importance, and classical shadows allow us to extract a large amount of information using relatively few measurements.

• Conventional shadow estimators are unbiased and thus approach the true mean in the infinite-sample limit.
• In this work, we consider a biased scheme, intentionally introducing a bias by rescaling the conventional classical shadows estimators can reduce the error in the finite-sample regime.
• The approach is straightforward to implement and requires no quantum resources.