방사광 X선 극저온 나노프로브 다이아몬드 주석-공공(SnV) 컬러센터 광학 스핀 양자 메모리 서보 C# SIMD 엔진

3. Zero-Allocation C# SIMD 다이아몬드 SnV 양자 메모리 서보 엔진

using System;
using System.Runtime.CompilerServices;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;

namespace ZeliDesk.Stem.Synchrotron.DiamondSnV
{
    public readonly ref struct SnVQuantumMemoryState
    {
        public readonly float SpinFidelity;
        public readonly float DetuningErrorMhz;
        public readonly float MicrowaveFrequencyOffsetMhz;
        public readonly bool QuantumCoherenceLocked;

        public SnVQuantumMemoryState(float fidelity, float detuning, float offset, bool locked)
        {
            SpinFidelity = fidelity;
            DetuningErrorMhz = detuning;
            MicrowaveFrequencyOffsetMhz = offset;
            QuantumCoherenceLocked = locked;
        }
    }

    public sealed class DiamondSnVMemoryServoEngine
    {
        private const float SampleRateHz = 100000.0f;
        private const float Dt = 1.0f / SampleRateHz;

        // 공명 주파수 목표 (3.25 GHz 마이크로웨이브 전이)
        private const float NominalResonanceGhz = 3.250f;

        // PI 제어기 상태
        private float _detuningIntegral = 0.0f;
        private float _prevDetuning = 0.0f;
        private const float KpMw = 0.55f;
        private const float KiMw = 120.0f;

        [MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
        public SnVQuantumMemoryState LockQubitPhase(
            float fluorescenceCountsSignal,
            float fluorescenceCountsReference,
            float magneticFieldGauss,
            float sampleTemperatureK)
        {
            // 1. 차등 광학 형광 신호로부터 라비 디튜닝 오차(MHz) 추정
            float sumCounts = fluorescenceCountsSignal + fluorescenceCountsReference;
            float contrast = (sumCounts > 1.0f) ? (fluorescenceCountsSignal - fluorescenceCountsReference) / sumCounts : 0.0f;

            // 콘트라스트 비례 디튜닝 주파수 변환 (약 25 MHz / 콘트라스트 단위)
            float estimatedDetuningMhz = contrast * 25.0f;

            // 2. PI 서보 보정 연산
            _detuningIntegral += estimatedDetuningMhz * Dt;
            _detuningIntegral = Math.Clamp(_detuningIntegral, -10.0f, 10.0f);

            float freqCorrectionMhz = (KpMw * estimatedDetuningMhz) + (KiMw * _detuningIntegral);

            // 3. 온도 및 스핀 완화 시간을 고려한 양자 상태 충실도(Fidelity) 추정
            // 4K 이하에서 T2* 감쇠 모델링
            float tempFactor = MathF.Max(0.1f, sampleTemperatureK / 4.0f);
            float effectiveT2Us = 500.0f / tempFactor;
            float fidelity = MathF.Exp(-MathF.Pow(estimatedDetuningMhz * 0.01f, 2.0f)) * (1.0f - 0.005f * tempFactor);
            fidelity = Math.Clamp(fidelity, 0.0f, 1.0f);

            bool isLocked = MathF.Abs(estimatedDetuningMhz) < 0.1f && fidelity >= 0.99f;

            return new SnVQuantumMemoryState(
                fidelity: fidelity,
                detuning: estimatedDetuningMhz,
                offset: freqCorrectionMhz,
                locked: isLocked
            );
        }
    }
}