Adding multiple measurements to model, see #54

phetsims · Jan 6, 2025 · 0fca8c1 · 0fca8c1
1 parent d9d7c2a
commit 0fca8c1
Show file tree

Hide file tree

Showing 2 changed files with 70 additions and 23 deletions.
diff --git a/js/bloch-sphere/model/BlochSphereModel.ts b/js/bloch-sphere/model/BlochSphereModel.ts
@@ -11,7 +11,6 @@ import BooleanProperty from '../../../../axon/js/BooleanProperty.js';
 import Multilink from '../../../../axon/js/Multilink.js';
 import NumberProperty from '../../../../axon/js/NumberProperty.js';
 import Property from '../../../../axon/js/Property.js';
-import dotRandom from '../../../../dot/js/dotRandom.js';
 import Range from '../../../../dot/js/Range.js';
 import TModel from '../../../../joist/js/TModel.js';
 import { EmptySelfOptions } from '../../../../phet-core/js/optionize.js';
@@ -34,6 +33,7 @@ export default class BlochSphereModel implements TModel {
 
   public readonly preparationBlochSphere: ComplexBlochSphere;
   public readonly singleMeasurementBlochSphere: ComplexBlochSphere;
+  public readonly multiMeasurementBlochSpheres: ComplexBlochSphere[] = [];
 
   // Coefficients of the state equation. They are derived from the Bloch Sphere representation on the multilink below.
   // |psi> = upCoefficient |up> + downCoefficient * exp( i * phase * PI ) |down>
@@ -79,7 +79,13 @@ export default class BlochSphereModel implements TModel {
     this.singleMeasurementBlochSphere = new ComplexBlochSphere( {
       tandem: providedOptions.tandem.createTandem( 'singleMeasurementBlochSphere' )
     } );
-    this.singleMeasurementBlochSphere.polarAngleProperty.value = Math.PI / 2;
+
+    const multiMeasurementTandem = providedOptions.tandem.createTandem( 'multiMeasurementBlochSpheres' );
+    _.times( 10, index => {
+      this.multiMeasurementBlochSpheres.push( new ComplexBlochSphere( {
+        tandem: multiMeasurementTandem.createTandem( `blochSphere${index}` )
+      } ) );
+    } );
 
     this.upCoefficientProperty = new NumberProperty( 0, {
       tandem: providedOptions.tandem.createTandem( 'upCoefficientProperty' ),
@@ -170,15 +176,26 @@ export default class BlochSphereModel implements TModel {
         this.singleMeasurementBlochSphere.rotatingSpeedProperty.value = selectedScene === BlochSphereScene.PRECESSION ?
                                                                         magneticFieldStrength :
                                                                         0;
+        this.multiMeasurementBlochSpheres.forEach( blochSphere => {
+          blochSphere.rotatingSpeedProperty.value = selectedScene === BlochSphereScene.PRECESSION ?
+                                                     magneticFieldStrength :
+                                                     0;
+        } );
       }
     );
 
     this.preparationBlochSphere.polarAngleProperty.link( polarAngle => {
       this.singleMeasurementBlochSphere.polarAngleProperty.value = polarAngle;
+      this.multiMeasurementBlochSpheres.forEach( blochSphere => {
+        blochSphere.polarAngleProperty.value = polarAngle;
+      } );
     } );
 
     this.preparationBlochSphere.azimuthalAngleProperty.link( azimuthalAngle => {
       this.singleMeasurementBlochSphere.azimuthalAngleProperty.value = azimuthalAngle;
+      this.multiMeasurementBlochSpheres.forEach( blochSphere => {
+        blochSphere.azimuthalAngleProperty.value = azimuthalAngle;
+      } );
     } );
 
     this.measurementBasisProperty.link( () => {
@@ -192,29 +209,13 @@ export default class BlochSphereModel implements TModel {
   public observe(): void {
     if ( this.readyToObserveProperty.value ) {
 
-      const measurementVector = StateDirection.directionToVector( this.measurementBasisProperty.value );
-      const stateVector = StateDirection.anglesToVector(
-        this.singleMeasurementBlochSphere.polarAngleProperty.value,
-        this.singleMeasurementBlochSphere.azimuthalAngleProperty.value
-      );
-
-      const dotProduct = measurementVector.dot( stateVector );
-
-      const isUp = ( dotRandom.nextDouble() * 2 - 1 ) < dotProduct;
-      if ( isUp ) {
-        this.upMeasurementCountProperty.value++;
-        this.singleMeasurementBlochSphere.setDirection(
-          this.measurementBasisProperty.value.polarAngle,
-          this.measurementBasisProperty.value.azimuthalAngle
-        );
+      if ( this.isSingleMeasurementModeProperty.value ) {
+        this.singleMeasurementBlochSphere.measure( this.measurementBasisProperty.value, this.upMeasurementCountProperty, this.downMeasurementCountProperty );
       }
       else {
-        this.downMeasurementCountProperty.value++;
-        const oppositeDirection = this.measurementBasisProperty.value.oppositeDirection;
-        this.singleMeasurementBlochSphere.setDirection(
-          oppositeDirection.polarAngle,
-          oppositeDirection.azimuthalAngle
-        );
+        this.multiMeasurementBlochSpheres.forEach( blochSphere => {
+          blochSphere.measure( this.measurementBasisProperty.value, this.upMeasurementCountProperty, this.downMeasurementCountProperty );
+        } );
       }
 
       // Update the measurement state.
@@ -233,6 +234,13 @@ export default class BlochSphereModel implements TModel {
       this.preparationBlochSphere.polarAngleProperty.value,
       this.preparationBlochSphere.azimuthalAngleProperty.value
     );
+
+    this.multiMeasurementBlochSpheres.forEach( blochSphere => {
+      blochSphere.setDirection(
+        this.preparationBlochSphere.polarAngleProperty.value,
+        this.preparationBlochSphere.azimuthalAngleProperty.value
+      );
+    } );
   }
 
   /**
@@ -262,6 +270,9 @@ export default class BlochSphereModel implements TModel {
    */
   public step( dt: number ): void {
     this.singleMeasurementBlochSphere.step( dt );
+    this.multiMeasurementBlochSpheres.forEach( blochSphere => {
+      blochSphere.step( dt );
+    } );
   }
 }
 

diff --git a/js/bloch-sphere/model/ComplexBlochSphere.ts b/js/bloch-sphere/model/ComplexBlochSphere.ts
@@ -8,12 +8,15 @@
  */
 
 import NumberProperty from '../../../../axon/js/NumberProperty.js';
+import dotRandom from '../../../../dot/js/dotRandom.js';
 import Range from '../../../../dot/js/Range.js';
 import Utils from '../../../../dot/js/Utils.js';
 import optionize from '../../../../phet-core/js/optionize.js';
 import { PhetioObjectOptions } from '../../../../tandem/js/PhetioObject.js';
 import AbstractBlochSphere, { AbstractBlochSphereOptions } from '../../common/model/AbstractBlochSphere.js';
 import quantumMeasurement from '../../quantumMeasurement.js';
+import { MeasurementBasis } from './MeasurementBasis.js';
+import { StateDirection } from './StateDirection.js';
 
 type SelfOptions = {
   initialRotationSpeed?: number;
@@ -56,6 +59,39 @@ export default class ComplexBlochSphere extends AbstractBlochSphere {
     this.azimuthalAngleProperty.value = azimuthalAngle;
   }
 
+  /**
+   * Given a measurement basis, measures along that axis and updates the counters accordingly.
+   * @param measurementBasis
+   * @param upCounterProperty
+   * @param downCounterProperty
+   */
+  public measure( measurementBasis: MeasurementBasis, upCounterProperty: NumberProperty, downCounterProperty: NumberProperty ): void {
+    const measurementVector = StateDirection.directionToVector( measurementBasis );
+    const stateVector = StateDirection.anglesToVector(
+      this.polarAngleProperty.value,
+      this.azimuthalAngleProperty.value
+    );
+
+    const dotProduct = measurementVector.dot( stateVector );
+
+    const isUp = ( dotRandom.nextDouble() * 2 - 1 ) < dotProduct;
+    if ( isUp ) {
+      upCounterProperty.value++;
+      this.setDirection(
+        measurementBasis.polarAngle,
+        measurementBasis.azimuthalAngle
+      );
+    }
+    else {
+      downCounterProperty.value++;
+      const oppositeDirection = measurementBasis.oppositeDirection;
+      this.setDirection(
+        oppositeDirection.polarAngle,
+        oppositeDirection.azimuthalAngle
+      );
+    }
+  }
+
   public override reset(): void {
     super.reset();
   }