Struct VirtualDistillation 

pub struct VirtualDistillation {
    pub num_copies: usize,
    pub use_symmetrization: bool,
    /* private fields */
}

Virtual Distillation error mitigation technique

Virtual Distillation uses multiple copies of a quantum state to create a “purified” version that suppresses errors. This technique is particularly effective for variational algorithms.

Reference: Koczor, B. (2021). “Exponential Error Suppression for Near-Term Quantum Devices”

Fields

num_copies: usize

Number of state copies to use

use_symmetrization: bool

Permutation group for symmetrization

Implementations

impl VirtualDistillation

pub fn new(num_copies: usize) -> Self

Create a new Virtual Distillation instance

pub fn mitigate_expectation( &mut self, raw_results: &[f64], observable: &Array1<Complex64>, ) -> Result<f64, QuantRS2Error>

Apply virtual distillation to measurement results

Arguments

• raw_results - Raw measurement outcomes from multiple circuit runs
• observable - The observable to measure (Pauli string representation)

Returns

Mitigated expectation value with reduced error

pub const fn error_suppression_factor(&self, base_error: f64) -> f64

Estimate error suppression factor

Virtual distillation provides exponential error suppression: ε_suppressed ≈ ε^n where n is the number of copies

Trait Implementations

impl Clone for VirtualDistillation

fn clone(&self) -> VirtualDistillation

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for VirtualDistillation

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.