quantrs2_sim/qml/
circuit.rs

1//! Parameterized quantum circuits for machine learning applications.
2//!
3//! This module provides parameterized quantum circuit structures with
4//! hardware-aware optimizations for different quantum computing architectures.
5
6use scirs2_core::ndarray::{Array1, Array2};
7use std::collections::HashMap;
8
9use super::config::HardwareArchitecture;
10use crate::circuit_interfaces::{InterfaceCircuit, InterfaceGateType};
11
12/// Parameterized quantum circuit for machine learning
13#[derive(Debug, Clone)]
14pub struct ParameterizedQuantumCircuit {
15    /// Circuit structure
16    pub circuit: InterfaceCircuit,
17    /// Parameter vector
18    pub parameters: Array1<f64>,
19    /// Parameter names for identification
20    pub parameter_names: Vec<String>,
21    /// Gate-to-parameter mapping
22    pub gate_parameter_map: HashMap<usize, Vec<usize>>,
23    /// Hardware-specific optimizations
24    pub hardware_optimizations: HardwareOptimizations,
25}
26
27/// Hardware-specific optimizations
28#[derive(Debug, Clone)]
29pub struct HardwareOptimizations {
30    /// Connectivity graph
31    pub connectivity_graph: Array2<bool>,
32    /// Gate fidelities
33    pub gate_fidelities: HashMap<String, f64>,
34    /// Decoherence times
35    pub decoherence_times: Array1<f64>,
36    /// Gate times
37    pub gate_times: HashMap<String, f64>,
38    /// Crosstalk matrix
39    pub crosstalk_matrix: Array2<f64>,
40}
41
42impl ParameterizedQuantumCircuit {
43    /// Create a new parameterized quantum circuit
44    pub fn new(
45        circuit: InterfaceCircuit,
46        parameters: Array1<f64>,
47        parameter_names: Vec<String>,
48        hardware_architecture: HardwareArchitecture,
49    ) -> Self {
50        let num_qubits = circuit.num_qubits;
51        let hardware_optimizations =
52            HardwareOptimizations::for_hardware(hardware_architecture, num_qubits);
53
54        Self {
55            circuit,
56            parameters,
57            parameter_names,
58            gate_parameter_map: HashMap::new(),
59            hardware_optimizations,
60        }
61    }
62
63    /// Update circuit parameters
64    pub fn update_parameters(&mut self, new_parameters: Array1<f64>) -> Result<(), String> {
65        if new_parameters.len() != self.parameters.len() {
66            return Err(format!(
67                "Parameter count mismatch: expected {}, got {}",
68                self.parameters.len(),
69                new_parameters.len()
70            ));
71        }
72        self.parameters = new_parameters;
73        Ok(())
74    }
75
76    /// Get parameter at specific index
77    pub fn get_parameter(&self, index: usize) -> Option<f64> {
78        self.parameters.get(index).copied()
79    }
80
81    /// Set parameter at specific index
82    pub fn set_parameter(&mut self, index: usize, value: f64) -> Result<(), String> {
83        if index >= self.parameters.len() {
84            return Err(format!("Parameter index {} out of bounds", index));
85        }
86        self.parameters[index] = value;
87        Ok(())
88    }
89
90    /// Get the number of parameters
91    pub fn num_parameters(&self) -> usize {
92        self.parameters.len()
93    }
94
95    /// Get the number of qubits
96    pub fn num_qubits(&self) -> usize {
97        self.circuit.num_qubits
98    }
99
100    /// Get circuit depth
101    pub fn depth(&self) -> usize {
102        self.circuit.gates.len()
103    }
104
105    /// Add parameter mapping for a gate
106    pub fn add_parameter_mapping(&mut self, gate_index: usize, parameter_indices: Vec<usize>) {
107        self.gate_parameter_map
108            .insert(gate_index, parameter_indices);
109    }
110
111    /// Get parameter mapping for a gate
112    pub fn get_parameter_mapping(&self, gate_index: usize) -> Option<&Vec<usize>> {
113        self.gate_parameter_map.get(&gate_index)
114    }
115
116    /// Estimate circuit fidelity based on hardware optimizations
117    pub fn estimate_fidelity(&self) -> f64 {
118        let mut total_fidelity = 1.0;
119
120        for gate in &self.circuit.gates {
121            let gate_name = Self::gate_type_to_string(&gate.gate_type);
122            if let Some(&fidelity) = self.hardware_optimizations.gate_fidelities.get(&gate_name) {
123                total_fidelity *= fidelity;
124            } else {
125                // Default fidelity for unknown gates
126                total_fidelity *= 0.99;
127            }
128        }
129
130        total_fidelity
131    }
132
133    /// Estimate total execution time
134    pub fn estimate_execution_time(&self) -> f64 {
135        let mut total_time = 0.0;
136
137        for gate in &self.circuit.gates {
138            let gate_name = Self::gate_type_to_string(&gate.gate_type);
139            if let Some(&time) = self.hardware_optimizations.gate_times.get(&gate_name) {
140                total_time += time;
141            } else {
142                // Default time for unknown gates
143                total_time += 1e-6;
144            }
145        }
146
147        total_time
148    }
149
150    /// Check if two qubits are connected according to hardware topology
151    pub fn are_qubits_connected(&self, qubit1: usize, qubit2: usize) -> bool {
152        if qubit1 >= self.num_qubits() || qubit2 >= self.num_qubits() {
153            return false;
154        }
155        self.hardware_optimizations.connectivity_graph[[qubit1, qubit2]]
156    }
157
158    /// Get decoherence time for a specific qubit
159    pub fn get_decoherence_time(&self, qubit: usize) -> Option<f64> {
160        self.hardware_optimizations
161            .decoherence_times
162            .get(qubit)
163            .copied()
164    }
165
166    /// Clone the circuit with new parameters
167    pub fn with_parameters(&self, parameters: Array1<f64>) -> Result<Self, String> {
168        let mut new_circuit = self.clone();
169        new_circuit.update_parameters(parameters)?;
170        Ok(new_circuit)
171    }
172
173    /// Convert InterfaceGateType to string
174    fn gate_type_to_string(gate_type: &InterfaceGateType) -> String {
175        match gate_type {
176            InterfaceGateType::Identity => "I".to_string(),
177            InterfaceGateType::PauliX | InterfaceGateType::X => "X".to_string(),
178            InterfaceGateType::PauliY => "Y".to_string(),
179            InterfaceGateType::PauliZ => "Z".to_string(),
180            InterfaceGateType::Hadamard | InterfaceGateType::H => "H".to_string(),
181            InterfaceGateType::S => "S".to_string(),
182            InterfaceGateType::T => "T".to_string(),
183            InterfaceGateType::Phase(_) => "Phase".to_string(),
184            InterfaceGateType::RX(_) => "RX".to_string(),
185            InterfaceGateType::RY(_) => "RY".to_string(),
186            InterfaceGateType::RZ(_) => "RZ".to_string(),
187            InterfaceGateType::U1(_) => "U1".to_string(),
188            InterfaceGateType::U2(_, _) => "U2".to_string(),
189            InterfaceGateType::U3(_, _, _) => "U3".to_string(),
190            InterfaceGateType::CNOT => "CNOT".to_string(),
191            InterfaceGateType::CZ => "CZ".to_string(),
192            InterfaceGateType::CY => "CY".to_string(),
193            InterfaceGateType::SWAP => "SWAP".to_string(),
194            InterfaceGateType::ISwap => "ISwap".to_string(),
195            InterfaceGateType::CRX(_) => "CRX".to_string(),
196            InterfaceGateType::CRY(_) => "CRY".to_string(),
197            InterfaceGateType::CRZ(_) => "CRZ".to_string(),
198            InterfaceGateType::CPhase(_) => "CPhase".to_string(),
199            InterfaceGateType::Toffoli => "Toffoli".to_string(),
200            InterfaceGateType::Fredkin => "Fredkin".to_string(),
201            InterfaceGateType::MultiControlledX(_) => "MCX".to_string(),
202            InterfaceGateType::MultiControlledZ(_) => "MCZ".to_string(),
203            InterfaceGateType::Custom(name, _) => name.clone(),
204            InterfaceGateType::Measure => "Measure".to_string(),
205            InterfaceGateType::Reset => "Reset".to_string(),
206        }
207    }
208}
209
210impl HardwareOptimizations {
211    /// Create optimizations for specific hardware
212    pub fn for_hardware(architecture: HardwareArchitecture, num_qubits: usize) -> Self {
213        let connectivity_graph = match architecture {
214            HardwareArchitecture::Superconducting => {
215                // Linear connectivity typical of superconducting systems
216                let mut graph = Array2::from_elem((num_qubits, num_qubits), false);
217                for i in 0..num_qubits.saturating_sub(1) {
218                    graph[[i, i + 1]] = true;
219                    graph[[i + 1, i]] = true;
220                }
221                graph
222            }
223            HardwareArchitecture::TrappedIon => {
224                // All-to-all connectivity for trapped ions
225                Array2::from_elem((num_qubits, num_qubits), true)
226            }
227            HardwareArchitecture::Photonic => {
228                // Limited connectivity for photonic systems
229                let mut graph = Array2::from_elem((num_qubits, num_qubits), false);
230                for i in 0..num_qubits {
231                    for j in 0..num_qubits {
232                        if (i as i32 - j as i32).abs() <= 2 {
233                            graph[[i, j]] = true;
234                        }
235                    }
236                }
237                graph
238            }
239            _ => Array2::from_elem((num_qubits, num_qubits), true),
240        };
241
242        let gate_fidelities = match architecture {
243            HardwareArchitecture::Superconducting => {
244                let mut fidelities = HashMap::new();
245                fidelities.insert("X".to_string(), 0.999);
246                fidelities.insert("Y".to_string(), 0.999);
247                fidelities.insert("Z".to_string(), 0.9999);
248                fidelities.insert("H".to_string(), 0.998);
249                fidelities.insert("CNOT".to_string(), 0.995);
250                fidelities.insert("CZ".to_string(), 0.996);
251                fidelities
252            }
253            HardwareArchitecture::TrappedIon => {
254                let mut fidelities = HashMap::new();
255                fidelities.insert("X".to_string(), 0.9999);
256                fidelities.insert("Y".to_string(), 0.9999);
257                fidelities.insert("Z".to_string(), 0.99999);
258                fidelities.insert("H".to_string(), 0.9999);
259                fidelities.insert("CNOT".to_string(), 0.999);
260                fidelities.insert("CZ".to_string(), 0.999);
261                fidelities
262            }
263            _ => {
264                let mut fidelities = HashMap::new();
265                fidelities.insert("X".to_string(), 0.99);
266                fidelities.insert("Y".to_string(), 0.99);
267                fidelities.insert("Z".to_string(), 0.999);
268                fidelities.insert("H".to_string(), 0.99);
269                fidelities.insert("CNOT".to_string(), 0.98);
270                fidelities.insert("CZ".to_string(), 0.98);
271                fidelities
272            }
273        };
274
275        let decoherence_times = match architecture {
276            HardwareArchitecture::Superconducting => {
277                Array1::from_vec(vec![50e-6; num_qubits]) // 50 microseconds
278            }
279            HardwareArchitecture::TrappedIon => {
280                Array1::from_vec(vec![100e-3; num_qubits]) // 100 milliseconds
281            }
282            _ => Array1::from_vec(vec![10e-6; num_qubits]),
283        };
284
285        let gate_times = match architecture {
286            HardwareArchitecture::Superconducting => {
287                let mut times = HashMap::new();
288                times.insert("X".to_string(), 20e-9);
289                times.insert("Y".to_string(), 20e-9);
290                times.insert("Z".to_string(), 0.0);
291                times.insert("H".to_string(), 20e-9);
292                times.insert("CNOT".to_string(), 40e-9);
293                times.insert("CZ".to_string(), 40e-9);
294                times
295            }
296            HardwareArchitecture::TrappedIon => {
297                let mut times = HashMap::new();
298                times.insert("X".to_string(), 10e-6);
299                times.insert("Y".to_string(), 10e-6);
300                times.insert("Z".to_string(), 0.0);
301                times.insert("H".to_string(), 10e-6);
302                times.insert("CNOT".to_string(), 100e-6);
303                times.insert("CZ".to_string(), 100e-6);
304                times
305            }
306            _ => {
307                let mut times = HashMap::new();
308                times.insert("X".to_string(), 1e-6);
309                times.insert("Y".to_string(), 1e-6);
310                times.insert("Z".to_string(), 0.0);
311                times.insert("H".to_string(), 1e-6);
312                times.insert("CNOT".to_string(), 10e-6);
313                times.insert("CZ".to_string(), 10e-6);
314                times
315            }
316        };
317
318        let crosstalk_matrix = Array2::zeros((num_qubits, num_qubits));
319
320        Self {
321            connectivity_graph,
322            gate_fidelities,
323            decoherence_times,
324            gate_times,
325            crosstalk_matrix,
326        }
327    }
328
329    /// Update gate fidelity for a specific gate
330    pub fn set_gate_fidelity(&mut self, gate_name: &str, fidelity: f64) {
331        self.gate_fidelities.insert(gate_name.to_string(), fidelity);
332    }
333
334    /// Update gate time for a specific gate
335    pub fn set_gate_time(&mut self, gate_name: &str, time: f64) {
336        self.gate_times.insert(gate_name.to_string(), time);
337    }
338
339    /// Update decoherence time for a specific qubit
340    pub fn set_decoherence_time(&mut self, qubit: usize, time: f64) {
341        if qubit < self.decoherence_times.len() {
342            self.decoherence_times[qubit] = time;
343        }
344    }
345
346    /// Set connectivity between two qubits
347    pub fn set_connectivity(&mut self, qubit1: usize, qubit2: usize, connected: bool) {
348        if qubit1 < self.connectivity_graph.nrows() && qubit2 < self.connectivity_graph.ncols() {
349            self.connectivity_graph[[qubit1, qubit2]] = connected;
350            self.connectivity_graph[[qubit2, qubit1]] = connected; // Symmetric
351        }
352    }
353
354    /// Get average gate fidelity
355    pub fn average_gate_fidelity(&self) -> f64 {
356        let fidelities: Vec<f64> = self.gate_fidelities.values().cloned().collect();
357        if fidelities.is_empty() {
358            1.0
359        } else {
360            fidelities.iter().sum::<f64>() / fidelities.len() as f64
361        }
362    }
363
364    /// Get connectivity degree (number of connections) for a qubit
365    pub fn connectivity_degree(&self, qubit: usize) -> usize {
366        if qubit >= self.connectivity_graph.nrows() {
367            return 0;
368        }
369        self.connectivity_graph
370            .row(qubit)
371            .iter()
372            .map(|&x| if x { 1 } else { 0 })
373            .sum()
374    }
375}
quantrs2_sim/qml/circuit.rs

quantrs2_sim/qml/
circuit.rs
