Skip to main content

quantrs2_sim/topological_quantum_simulation/
topologicalquantumsimulator_encoding.rs

1//! # TopologicalQuantumSimulator - encoding Methods
2//!
3//! This module contains method implementations for `TopologicalQuantumSimulator`.
4//!
5//! 🤖 Generated with [SplitRS](https://github.com/cool-japan/splitrs)
6
7use crate::error::{Result, SimulatorError};
8use scirs2_core::ndarray::{Array1, Array2, Array3, Array4, Axis};
9use scirs2_core::Complex64;
10use std::collections::{HashMap, HashSet, VecDeque};
11
12use super::functions::AnyonModelImplementation;
13use super::types::{
14    AbelianAnyons, AnyonConfiguration, AnyonModel, AnyonType, AnyonWorldline, BraidingOperation,
15    BraidingType, ChernSimonsAnyons, FibonacciAnyons, IsingAnyons, LatticeType, LogicalOperators,
16    NonAbelianAnyons, ParafermionAnyons, StabilizerType, SurfaceCode, SyndromeDetector,
17    TopologicalConfig, TopologicalErrorCode, TopologicalInvariants, TopologicalLattice,
18    TopologicalSimulationStats, TopologicalState,
19};
20
21use super::topologicalquantumsimulator_type::TopologicalQuantumSimulator;
22
23impl TopologicalQuantumSimulator {
24    /// Create new topological quantum simulator
25    pub fn new(config: TopologicalConfig) -> Result<Self> {
26        let lattice = Self::create_lattice(&config)?;
27        let anyon_model = Self::create_anyon_model(&config.anyon_model)?;
28        let initial_state = Self::create_initial_topological_state(&config, &lattice)?;
29        let error_correction = if config.topological_protection {
30            Some(Self::create_surface_code(&config, &lattice)?)
31        } else {
32            None
33        };
34        Ok(Self {
35            config,
36            state: initial_state,
37            lattice,
38            anyon_model,
39            error_correction,
40            braiding_history: Vec::new(),
41            stats: TopologicalSimulationStats::default(),
42        })
43    }
44    /// Create lattice structure
45    pub(super) fn create_lattice(config: &TopologicalConfig) -> Result<TopologicalLattice> {
46        match config.lattice_type {
47            LatticeType::SquareLattice => Self::create_square_lattice(&config.dimensions),
48            LatticeType::TriangularLattice => Self::create_triangular_lattice(&config.dimensions),
49            LatticeType::HexagonalLattice => Self::create_hexagonal_lattice(&config.dimensions),
50            LatticeType::HoneycombLattice => Self::create_honeycomb_lattice(&config.dimensions),
51            LatticeType::KagomeLattice => Self::create_kagome_lattice(&config.dimensions),
52            LatticeType::CustomLattice => Self::create_custom_lattice(&config.dimensions),
53        }
54    }
55    /// Create square lattice
56    pub(super) fn create_square_lattice(dimensions: &[usize]) -> Result<TopologicalLattice> {
57        if dimensions.len() != 2 {
58            return Err(SimulatorError::InvalidInput(
59                "Square lattice requires 2D dimensions".to_string(),
60            ));
61        }
62        let (width, height) = (dimensions[0], dimensions[1]);
63        let mut sites = Vec::new();
64        let mut bonds = Vec::new();
65        let mut plaquettes = Vec::new();
66        for y in 0..height {
67            for x in 0..width {
68                sites.push(vec![x as f64, y as f64]);
69            }
70        }
71        for y in 0..height {
72            for x in 0..width {
73                let site = y * width + x;
74                if x < width - 1 {
75                    bonds.push((site, site + 1));
76                }
77                if y < height - 1 {
78                    bonds.push((site, site + width));
79                }
80            }
81        }
82        for y in 0..height - 1 {
83            for x in 0..width - 1 {
84                let plaquette = vec![
85                    y * width + x,
86                    y * width + x + 1,
87                    (y + 1) * width + x,
88                    (y + 1) * width + x + 1,
89                ];
90                plaquettes.push(plaquette);
91            }
92        }
93        Ok(TopologicalLattice {
94            lattice_type: LatticeType::SquareLattice,
95            dimensions: dimensions.to_vec(),
96            sites,
97            bonds,
98            plaquettes,
99            coordination_number: 4,
100        })
101    }
102    /// Create triangular lattice
103    pub(super) fn create_triangular_lattice(dimensions: &[usize]) -> Result<TopologicalLattice> {
104        if dimensions.len() != 2 {
105            return Err(SimulatorError::InvalidInput(
106                "Triangular lattice requires 2D dimensions".to_string(),
107            ));
108        }
109        let (width, height) = (dimensions[0], dimensions[1]);
110        let mut sites = Vec::new();
111        let mut bonds = Vec::new();
112        let mut plaquettes = Vec::new();
113        for y in 0..height {
114            for x in 0..width {
115                let x_pos = x as f64 + if y % 2 == 1 { 0.5 } else { 0.0 };
116                let y_pos = y as f64 * 3.0_f64.sqrt() / 2.0;
117                sites.push(vec![x_pos, y_pos]);
118            }
119        }
120        for y in 0..height {
121            for x in 0..width {
122                let site = y * width + x;
123                if x < width - 1 {
124                    bonds.push((site, site + 1));
125                }
126                if y < height - 1 {
127                    bonds.push((site, site + width));
128                    if y % 2 == 0 && x < width - 1 {
129                        bonds.push((site, site + width + 1));
130                    } else if y % 2 == 1 && x > 0 {
131                        bonds.push((site, site + width - 1));
132                    }
133                }
134            }
135        }
136        for y in 0..height - 1 {
137            for x in 0..width - 1 {
138                if y % 2 == 0 {
139                    let plaquette = vec![y * width + x, y * width + x + 1, (y + 1) * width + x];
140                    plaquettes.push(plaquette);
141                }
142            }
143        }
144        Ok(TopologicalLattice {
145            lattice_type: LatticeType::TriangularLattice,
146            dimensions: dimensions.to_vec(),
147            sites,
148            bonds,
149            plaquettes,
150            coordination_number: 6,
151        })
152    }
153    /// Create hexagonal lattice
154    pub(super) fn create_hexagonal_lattice(dimensions: &[usize]) -> Result<TopologicalLattice> {
155        if dimensions.len() != 2 {
156            return Err(SimulatorError::InvalidInput(
157                "Hexagonal lattice requires 2D dimensions".to_string(),
158            ));
159        }
160        let (width, height) = (dimensions[0], dimensions[1]);
161        let mut sites = Vec::new();
162        let mut bonds = Vec::new();
163        let mut plaquettes = Vec::new();
164        for y in 0..height {
165            for x in 0..width {
166                let x_pos = x as f64 * 1.5;
167                let y_pos = (y as f64).mul_add(
168                    3.0_f64.sqrt(),
169                    if x % 2 == 1 {
170                        3.0_f64.sqrt() / 2.0
171                    } else {
172                        0.0
173                    },
174                );
175                sites.push(vec![x_pos, y_pos]);
176            }
177        }
178        for y in 0..height {
179            for x in 0..width {
180                let site = y * width + x;
181                if x < width - 1 {
182                    bonds.push((site, site + 1));
183                }
184                if y < height - 1 {
185                    bonds.push((site, site + width));
186                }
187                if y > 0 {
188                    bonds.push((site, site - width));
189                }
190            }
191        }
192        for y in 1..height - 1 {
193            for x in 1..width - 1 {
194                let plaquette = vec![
195                    (y - 1) * width + x,
196                    (y - 1) * width + x + 1,
197                    y * width + x + 1,
198                    (y + 1) * width + x + 1,
199                    (y + 1) * width + x,
200                    y * width + x,
201                ];
202                plaquettes.push(plaquette);
203            }
204        }
205        Ok(TopologicalLattice {
206            lattice_type: LatticeType::HexagonalLattice,
207            dimensions: dimensions.to_vec(),
208            sites,
209            bonds,
210            plaquettes,
211            coordination_number: 3,
212        })
213    }
214    /// Create honeycomb lattice (for Kitaev model)
215    pub(super) fn create_honeycomb_lattice(dimensions: &[usize]) -> Result<TopologicalLattice> {
216        if dimensions.len() != 2 {
217            return Err(SimulatorError::InvalidInput(
218                "Honeycomb lattice requires 2D dimensions".to_string(),
219            ));
220        }
221        let (width, height) = (dimensions[0], dimensions[1]);
222        let mut sites = Vec::new();
223        let mut bonds = Vec::new();
224        let mut plaquettes = Vec::new();
225        for y in 0..height {
226            for x in 0..width {
227                let x_a = x as f64 * 3.0 / 2.0;
228                let y_a = y as f64 * 3.0_f64.sqrt();
229                sites.push(vec![x_a, y_a]);
230                let x_b = x as f64 * 3.0 / 2.0 + 1.0;
231                let y_b = (y as f64).mul_add(3.0_f64.sqrt(), 3.0_f64.sqrt() / 3.0);
232                sites.push(vec![x_b, y_b]);
233            }
234        }
235        for y in 0..height {
236            for x in 0..width {
237                let a_site = 2 * (y * width + x);
238                let b_site = a_site + 1;
239                bonds.push((a_site, b_site));
240                if x < width - 1 {
241                    bonds.push((b_site, a_site + 2));
242                }
243                if y < height - 1 {
244                    bonds.push((b_site, a_site + 2 * width));
245                }
246            }
247        }
248        for y in 0..height - 1 {
249            for x in 0..width - 1 {
250                let plaquette = vec![
251                    2 * (y * width + x),
252                    2 * (y * width + x) + 1,
253                    2 * (y * width + x + 1),
254                    2 * (y * width + x + 1) + 1,
255                    2 * ((y + 1) * width + x),
256                    2 * ((y + 1) * width + x) + 1,
257                ];
258                plaquettes.push(plaquette);
259            }
260        }
261        Ok(TopologicalLattice {
262            lattice_type: LatticeType::HoneycombLattice,
263            dimensions: dimensions.to_vec(),
264            sites,
265            bonds,
266            plaquettes,
267            coordination_number: 3,
268        })
269    }
270    /// Create Kagome lattice
271    pub(super) fn create_kagome_lattice(dimensions: &[usize]) -> Result<TopologicalLattice> {
272        if dimensions.len() != 2 {
273            return Err(SimulatorError::InvalidInput(
274                "Kagome lattice requires 2D dimensions".to_string(),
275            ));
276        }
277        let (width, height) = (dimensions[0], dimensions[1]);
278        let mut sites = Vec::new();
279        let mut bonds = Vec::new();
280        let mut plaquettes = Vec::new();
281        for y in 0..height {
282            for x in 0..width {
283                let base_x = x as f64 * 2.0;
284                let base_y = y as f64 * 3.0_f64.sqrt();
285                sites.push(vec![base_x, base_y]);
286                sites.push(vec![base_x + 1.0, base_y]);
287                sites.push(vec![base_x + 0.5, base_y + 3.0_f64.sqrt() / 2.0]);
288            }
289        }
290        for y in 0..height {
291            for x in 0..width {
292                let base_site = 3 * (y * width + x);
293                bonds.push((base_site, base_site + 1));
294                bonds.push((base_site + 1, base_site + 2));
295                bonds.push((base_site + 2, base_site));
296                if x < width - 1 {
297                    bonds.push((base_site + 1, base_site + 3));
298                }
299                if y < height - 1 {
300                    bonds.push((base_site + 2, base_site + 3 * width));
301                }
302            }
303        }
304        for y in 0..height {
305            for x in 0..width {
306                let base_site = 3 * (y * width + x);
307                let triangle = vec![base_site, base_site + 1, base_site + 2];
308                plaquettes.push(triangle);
309                if x < width - 1 && y < height - 1 {
310                    let hexagon = vec![
311                        base_site + 1,
312                        base_site + 3,
313                        base_site + 3 + 2,
314                        base_site + 3 * width + 2,
315                        base_site + 3 * width,
316                        base_site + 2,
317                    ];
318                    plaquettes.push(hexagon);
319                }
320            }
321        }
322        Ok(TopologicalLattice {
323            lattice_type: LatticeType::KagomeLattice,
324            dimensions: dimensions.to_vec(),
325            sites,
326            bonds,
327            plaquettes,
328            coordination_number: 4,
329        })
330    }
331    /// Create anyon model implementation
332    pub(super) fn create_anyon_model(
333        model: &AnyonModel,
334    ) -> Result<Box<dyn AnyonModelImplementation + Send + Sync>> {
335        match model {
336            AnyonModel::Abelian => Ok(Box::new(AbelianAnyons::new())),
337            AnyonModel::NonAbelian => Ok(Box::new(NonAbelianAnyons::new())),
338            AnyonModel::Fibonacci => Ok(Box::new(FibonacciAnyons::new())),
339            AnyonModel::Ising => Ok(Box::new(IsingAnyons::new())),
340            AnyonModel::Parafermion => Ok(Box::new(ParafermionAnyons::new())),
341            AnyonModel::ChernSimons(k) => Ok(Box::new(ChernSimonsAnyons::new(*k))),
342        }
343    }
344    /// Create initial topological state
345    pub(super) fn create_initial_topological_state(
346        config: &TopologicalConfig,
347        lattice: &TopologicalLattice,
348    ) -> Result<TopologicalState> {
349        let anyon_config = AnyonConfiguration {
350            anyons: Vec::new(),
351            worldlines: Vec::new(),
352            fusion_tree: None,
353            total_charge: 0,
354        };
355        let degeneracy = Self::calculate_ground_state_degeneracy(config, lattice);
356        let amplitudes = Array1::zeros(degeneracy);
357        let topological_invariants = TopologicalInvariants::default();
358        Ok(TopologicalState {
359            anyon_config,
360            amplitudes,
361            degeneracy,
362            topological_invariants,
363            energy_gap: config.magnetic_field,
364        })
365    }
366    /// Create surface code for error correction
367    pub(super) fn create_surface_code(
368        config: &TopologicalConfig,
369        lattice: &TopologicalLattice,
370    ) -> Result<SurfaceCode> {
371        match config.error_correction_code {
372            TopologicalErrorCode::SurfaceCode => {
373                Self::create_toric_surface_code(&config.dimensions)
374            }
375            TopologicalErrorCode::ColorCode => Self::create_color_code(&config.dimensions),
376            _ => Self::create_toric_surface_code(&config.dimensions),
377        }
378    }
379    /// Create toric surface code
380    pub(super) fn create_toric_surface_code(dimensions: &[usize]) -> Result<SurfaceCode> {
381        if dimensions.len() != 2 {
382            return Err(SimulatorError::InvalidInput(
383                "Surface code requires 2D lattice".to_string(),
384            ));
385        }
386        let distance = dimensions[0].min(dimensions[1]);
387        let mut data_qubits = Vec::new();
388        let mut x_stabilizers = Vec::new();
389        let mut z_stabilizers = Vec::new();
390        for y in 0..distance {
391            for x in 0..distance {
392                data_qubits.push(vec![x, y, 0]);
393                data_qubits.push(vec![x, y, 1]);
394            }
395        }
396        for y in 0..distance {
397            for x in 0..distance {
398                let stabilizer_pos = vec![x, y];
399                x_stabilizers.push(stabilizer_pos);
400            }
401        }
402        for y in 0..distance - 1 {
403            for x in 0..distance - 1 {
404                let stabilizer_pos = vec![x, y];
405                z_stabilizers.push(stabilizer_pos);
406            }
407        }
408        let logical_x = vec![Array1::from_elem(distance, true)];
409        let logical_z = vec![Array1::from_elem(distance, true)];
410        let logical_operators = LogicalOperators {
411            logical_x,
412            logical_z,
413            num_logical_qubits: 1,
414        };
415        let mut syndrome_detectors = Vec::new();
416        for stabilizer in &x_stabilizers {
417            let detector = SyndromeDetector {
418                stabilizer_type: StabilizerType::PauliX,
419                measured_qubits: vec![0, 1, 2, 3],
420                threshold: 0.5,
421                correction_map: HashMap::new(),
422            };
423            syndrome_detectors.push(detector);
424        }
425        for stabilizer in &z_stabilizers {
426            let detector = SyndromeDetector {
427                stabilizer_type: StabilizerType::PauliZ,
428                measured_qubits: vec![0, 1, 2, 3],
429                threshold: 0.5,
430                correction_map: HashMap::new(),
431            };
432            syndrome_detectors.push(detector);
433        }
434        Ok(SurfaceCode {
435            distance,
436            data_qubits,
437            x_stabilizers,
438            z_stabilizers,
439            logical_operators,
440            syndrome_detectors,
441        })
442    }
443    /// Place anyon on the lattice
444    pub fn place_anyon(&mut self, anyon_type: AnyonType, position: Vec<usize>) -> Result<usize> {
445        if position.len() != self.config.dimensions.len() {
446            return Err(SimulatorError::InvalidInput(
447                "Position dimension mismatch".to_string(),
448            ));
449        }
450        for (i, &pos) in position.iter().enumerate() {
451            if pos >= self.config.dimensions[i] {
452                return Err(SimulatorError::InvalidInput(
453                    "Position out of bounds".to_string(),
454                ));
455            }
456        }
457        let anyon_id = self.state.anyon_config.anyons.len();
458        self.state
459            .anyon_config
460            .anyons
461            .push((position.clone(), anyon_type.clone()));
462        self.state.anyon_config.total_charge += anyon_type.topological_charge;
463        let worldline = AnyonWorldline {
464            anyon_type,
465            path: vec![position],
466            time_stamps: vec![0.0],
467            accumulated_phase: Complex64::new(1.0, 0.0),
468        };
469        self.state.anyon_config.worldlines.push(worldline);
470        Ok(anyon_id)
471    }
472    /// Perform braiding operation between two anyons
473    pub fn braid_anyons(
474        &mut self,
475        anyon_a: usize,
476        anyon_b: usize,
477        braiding_type: BraidingType,
478    ) -> Result<Complex64> {
479        let start_time = std::time::Instant::now();
480        if anyon_a >= self.state.anyon_config.anyons.len()
481            || anyon_b >= self.state.anyon_config.anyons.len()
482        {
483            return Err(SimulatorError::InvalidInput(
484                "Invalid anyon indices".to_string(),
485            ));
486        }
487        let (_, ref type_a) = &self.state.anyon_config.anyons[anyon_a];
488        let (_, ref type_b) = &self.state.anyon_config.anyons[anyon_b];
489        let braiding_matrix = self.anyon_model.braiding_matrix(type_a, type_b);
490        let braiding_phase = match braiding_type {
491            BraidingType::Clockwise => type_a.r_matrix * type_b.r_matrix.conj(),
492            BraidingType::Counterclockwise => type_a.r_matrix.conj() * type_b.r_matrix,
493            BraidingType::Exchange => type_a.r_matrix * type_b.r_matrix,
494            BraidingType::Identity => Complex64::new(1.0, 0.0),
495        };
496        let current_time = self.braiding_history.len() as f64;
497        if anyon_a < self.state.anyon_config.worldlines.len() {
498            self.state.anyon_config.worldlines[anyon_a]
499                .time_stamps
500                .push(current_time);
501            self.state.anyon_config.worldlines[anyon_a].accumulated_phase *= braiding_phase;
502        }
503        if anyon_b < self.state.anyon_config.worldlines.len() {
504            self.state.anyon_config.worldlines[anyon_b]
505                .time_stamps
506                .push(current_time);
507            self.state.anyon_config.worldlines[anyon_b].accumulated_phase *= braiding_phase.conj();
508        }
509        for amplitude in &mut self.state.amplitudes {
510            *amplitude *= braiding_phase;
511        }
512        let execution_time = start_time.elapsed().as_secs_f64() * 1000.0;
513        let braiding_op = BraidingOperation {
514            anyon_indices: vec![anyon_a, anyon_b],
515            braiding_type,
516            braiding_matrix,
517            execution_time,
518        };
519        self.braiding_history.push(braiding_op);
520        self.stats.braiding_operations += 1;
521        self.stats.avg_braiding_time_ms = self
522            .stats
523            .avg_braiding_time_ms
524            .mul_add((self.stats.braiding_operations - 1) as f64, execution_time)
525            / self.stats.braiding_operations as f64;
526        Ok(braiding_phase)
527    }
528    /// Create anyon from label
529    pub(super) fn create_anyon_from_label(&self, label: &str) -> Result<AnyonType> {
530        match label {
531            "vacuum" => Ok(AnyonType::vacuum()),
532            "sigma" => Ok(AnyonType::sigma()),
533            "tau" => Ok(AnyonType::tau()),
534            _ => Ok(AnyonType {
535                label: label.to_string(),
536                quantum_dimension: 1.0,
537                topological_charge: 0,
538                fusion_rules: HashMap::new(),
539                r_matrix: Complex64::new(1.0, 0.0),
540                is_abelian: true,
541            }),
542        }
543    }
544    /// Calculate Berry phase
545    pub(super) fn calculate_berry_phase(&self) -> Result<f64> {
546        let total_braiding_phase: Complex64 = self
547            .state
548            .anyon_config
549            .worldlines
550            .iter()
551            .map(|wl| wl.accumulated_phase)
552            .fold(Complex64::new(1.0, 0.0), |acc, phase| acc * phase);
553        Ok(total_braiding_phase.arg())
554    }
555    /// Detect and correct topological errors
556    pub fn detect_and_correct_errors(&mut self) -> Result<Vec<bool>> {
557        if let Some(ref surface_code) = self.error_correction {
558            let mut syndrome = Vec::new();
559            for detector in &surface_code.syndrome_detectors {
560                let measurement = self.measure_stabilizer(detector)?;
561                syndrome.push(measurement);
562            }
563            let corrections = self.decode_syndrome(&syndrome)?;
564            self.apply_corrections(&corrections)?;
565            self.stats.error_corrections += 1;
566            Ok(syndrome)
567        } else {
568            Ok(Vec::new())
569        }
570    }
571    /// Decode error syndrome
572    pub(super) fn decode_syndrome(&self, syndrome: &[bool]) -> Result<Vec<usize>> {
573        let mut corrections = Vec::new();
574        for (i, &error) in syndrome.iter().enumerate() {
575            if error {
576                corrections.push(i);
577            }
578        }
579        Ok(corrections)
580    }
581    /// Apply error corrections
582    pub(super) fn apply_corrections(&mut self, corrections: &[usize]) -> Result<()> {
583        for &correction_site in corrections {
584            if correction_site < self.state.amplitudes.len() {
585                self.state.amplitudes[correction_site] *= Complex64::new(-1.0, 0.0);
586            }
587        }
588        Ok(())
589    }
590}