극저온 테라헤르츠 주사 터널링 현미경(THz-STM) 서브피코초 광펄스 전계 구동 단일 분자 궤도 전이 C# 실시간 SIMD 서보 엔진

3. Zero-Allocation C# SIMD THz-STM 과도 서보 엔진 구현

광학 지연선 피에조 위치 신호와 락인 앰프 차동 전하 계수 신호를 수신하여 팁 간극 Z-서보 및 THz 지연선 스캔을 10,000 Hz로 실시간 통제하는 C# .NET 9.0 엔진입니다.

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

namespace ZeliDesk.Quantum.ThzStmNanoscopy
{
    public readonly ref struct ThzStmTelemetry
    {
        public readonly float RectifiedCurrentPicoAmps;  // Average rectified current
        public readonly float DelayStagePositionPs;      // Delay tau (-5.0 to +15.0 ps)
        public readonly float TipSampleBiasVoltageDcV;   // V_DC (e.g. -1.25 V)
        public readonly float PeakThzElectricFieldKvPerCm;
        public readonly float CryostatTempKelvin;        // 4.2 K

        public ThzStmTelemetry(float iRect, float tauPs, float vDc, float eThz, float tempK)
        {
            RectifiedCurrentPicoAmps = iRect;
            DelayStagePositionPs = tauPs;
            TipSampleBiasVoltageDcV = vDc;
            PeakThzElectricFieldKvPerCm = eThz;
            CryostatTempKelvin = tempK;
        }
    }

    public ref struct ThzStmServoResult
    {
        public float PiezoZGapAdjustmentPm;
        public float ElectronsPerThzPulse;
        public float InstantaneousGapVoltageV;
        public float TargetDelayStageSpeedUmPerSec;
        public bool SingleElectronOrbitalTransitionLocked;
    }

    public static class TerahertzScanningTunnelingEngine
    {
        private const float LaserRepetitionRateHz = 80.0e6f; // 80 MHz Ti:Sapphire rep rate
        private const float ElectronCharge = 1.602e-19f;

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static void ProcessTransientStep(
            in ThzStmTelemetry telemetry,
            ref ThzStmServoResult output)
        {
            // 1. Calculate Transferred Electrons Per Pulse
            //  = Delta Q * f_rep = (N_e * e) * f_rep
            float iRectAmps = telemetry.RectifiedCurrentPicoAmps * 1.0e-12f;
            float electronsPerPulse = iRectAmps / (ElectronCharge * LaserRepetitionRateHz);
            output.ElectronsPerThzPulse = electronsPerPulse;

            // 2. Closed-Loop Z-Height Nanogap Stabilization
            // Maintain single-electron regime: target 0.85 electrons / pulse
            float electronTarget = 0.85f;
            float error = electronsPerPulse - electronTarget;

            // Piezo Z adjustment in picometers (tunneling current varies exponentially)
            float zStepPm = -error * 12.5f; // pm per electron error
            output.PiezoZGapAdjustmentPm = Math.Clamp(zStepPm, -50.0f, 50.0f);

            // 3. Peak Gap Voltage under THz Pulse
            // V_gap = field_enhancement * gap * E_thz
            float enhancementFactor = 12500.0f;
            float gapDistanceM = 0.8e-9f; // 0.8 nm gap
            float eThzVpm = telemetry.PeakThzElectricFieldKvPerCm * 1.0e5f;
            float vPeakThz = enhancementFactor * gapDistanceM * eThzVpm;
            output.InstantaneousGapVoltageV = vPeakThz;

            // 4. Optical Delay Stage Servo Velocity
            // Constant velocity scan: 5.0 um/s for sub-picosecond waveform raster
            output.TargetDelayStageSpeedUmPerSec = 5.0f;

            // Transition lock criteria: N_e ~ 0.5 - 1.5 electrons/pulse
            output.SingleElectronOrbitalTransitionLocked = (electronsPerPulse >= 0.5f && electronsPerPulse <= 1.5f && MathF.Abs(output.PiezoZGapAdjustmentPm) < 5.0f);
        }
    }
}