open-standards/wai/wai-web/src/quantum_control.rs

//! Filter-function control + noise spectroscopy in the browser (`wai.quantum.cal.*`,
//! frequency domain). The SAME deterministic fixed-point DSP a native sink runs,
//! compiled to wasm32: reconstruct a *hidden* noise PSD from a dynamical-decoupling
//! filter bank, and reshape a DD sequence so its filter's stopband sits over the
//! noise — byte-exact, each sealing a `wai.quantum.calibration` receipt. The
//! matched pair that extends the calibration suite to correlated / 1-f noise.

use ed25519_dalek::SigningKey;
use wai::quantum_control::{
    dd_cpmg, optimize_dd, psd_model, reconstruct_psd, NoiseGrid, RobustResult, SpectroResult,
};
use wai::quantum_ops::GrantRef;
use wasm_bindgen::prelude::*;

const ONE: f64 = (1u64 << 20) as f64;
fn f(v: i64) -> f64 {
    v as f64 / ONE
}
fn signer() -> SigningKey {
    SigningKey::from_bytes(&[0x51; 32])
}
fn grant() -> GrantRef {
    GrantRef::unbounded("quantum.calibrate")
}
fn base_grid() -> NoiseGrid {
    NoiseGrid::linear(0.5, 90.0, 180)
}

// ===========================================================================
// 1. Noise spectroscopy — recover a hidden PSD from a DD filter bank
// ===========================================================================

#[wasm_bindgen]
pub struct SpectroDemo {
    g: NoiseGrid,
    res: SpectroResult,
}

#[wasm_bindgen]
impl SpectroDemo {
    /// Reconstruct a hidden `1/f + Lorentzian-bump` PSD from a bank of CPMG
    /// filters, each a narrow-band probe. `seed` varies the sampling noise.
    #[wasm_bindgen(constructor)]
    pub fn new(seed: f64) -> SpectroDemo {
        let g = base_grid();
        let psd = psd_model(&g, 0.02, 0.6, 25.0, 5.0);
        let res = reconstruct_psd(&g, &psd, 20, 40_000, 40, seed as u64);
        SpectroDemo { g, res }
    }
    pub fn omega(&self) -> Vec<f64> {
        self.g.omega.iter().map(|&w| f(w)).collect()
    }
    pub fn psd_true(&self) -> Vec<f64> {
        self.res.psd_true.iter().map(|&v| f(v)).collect()
    }
    pub fn psd_est(&self) -> Vec<f64> {
        self.res.psd_est.iter().map(|&v| f(v)).collect()
    }
    pub fn n_sequences(&self) -> u32 {
        self.res.n_sequences as u32
    }
    pub fn error(&self) -> f64 {
        f(self.res.error_fx)
    }
    pub fn mean_psd(&self) -> f64 {
        f(self.res.psd_true.iter().sum::<i64>() / self.res.psd_true.len().max(1) as i64)
    }
    pub fn receipt_json(&self) -> String {
        self.res.seal(&signer(), "did:key:demo-lab", 1_000_000, grant()).to_json()
    }
    pub fn receipt_verifies(&self) -> bool {
        self.res.seal(&signer(), "did:key:demo-lab", 1_000_000, grant()).verify()
    }
}

// ===========================================================================
// 2. Filter-function robust control — reshape a DD sequence to dodge the PSD
// ===========================================================================

#[wasm_bindgen]
pub struct RobustFFDemo {
    g: NoiseGrid,
    psd: Vec<i64>,
    res: RobustResult,
    n: u32,
}

#[wasm_bindgen]
impl RobustFFDemo {
    /// Reshape an `n`-pulse DD sequence to minimise the filter overlap against a
    /// `1/f + bump` PSD whose bump sits right under equal-spaced CPMG's passband.
    #[wasm_bindgen(constructor)]
    pub fn new(n: u32, seed: f64) -> RobustFFDemo {
        let g = base_grid();
        // bump location jittered by seed so "new spectrum" reshapes differently
        let w0 = 22.0 + (seed as u64 % 12) as f64;
        let psd = psd_model(&g, 0.02, 0.6, w0, 5.0);
        let res = optimize_dd(&g, &psd, n as usize, 40);
        RobustFFDemo { g, psd, res, n }
    }
    pub fn omega(&self) -> Vec<f64> {
        self.g.omega.iter().map(|&w| f(w)).collect()
    }
    pub fn psd(&self) -> Vec<f64> {
        self.psd.iter().map(|&v| f(v)).collect()
    }
    pub fn kern_cpmg(&self) -> Vec<f64> {
        self.res.kern_cpmg.iter().map(|&v| f(v)).collect()
    }
    pub fn kern_opt(&self) -> Vec<f64> {
        self.res.kern_opt.iter().map(|&v| f(v)).collect()
    }
    pub fn chi_cpmg(&self) -> f64 {
        f(self.res.chi_cpmg)
    }
    pub fn chi_opt(&self) -> f64 {
        f(self.res.chi_opt)
    }
    pub fn coh_cpmg(&self) -> f64 {
        f(self.res.coh_cpmg)
    }
    pub fn coh_opt(&self) -> f64 {
        f(self.res.coh_opt)
    }
    pub fn improvement(&self) -> f64 {
        f(self.res.improvement_fx())
    }
    pub fn n_pulses(&self) -> u32 {
        self.n
    }
    /// Equal-spaced CPMG pulse positions (in [0,1]).
    pub fn pulses_cpmg(&self) -> Vec<f64> {
        dd_cpmg(self.n as usize).iter().map(|&p| f(p)).collect()
    }
    /// The optimised (reshaped) pulse positions.
    pub fn pulses_opt(&self) -> Vec<f64> {
        self.res.pulses.iter().map(|&p| f(p)).collect()
    }
    pub fn receipt_json(&self) -> String {
        self.res.seal(&signer(), "did:key:demo-lab", 1_000_000, grant()).to_json()
    }
    pub fn receipt_verifies(&self) -> bool {
        self.res.seal(&signer(), "did:key:demo-lab", 1_000_000, grant()).verify()
    }
}