microsoft/qdk
Publicmirrored from https://github.com/microsoft/qdkAvailable
source/noisy_simulator/src/tests/noiseless_tests.rs
325lines · modecode
| 1 | // Copyright (c) Microsoft Corporation. |
| 2 | // Licensed under the MIT License. |
| 3 | |
| 4 | use crate::{ |
| 5 | instrument::Instrument, |
| 6 | operation::{operation, Operation}, |
| 7 | NoisySimulator, |
| 8 | }; |
| 9 | use num_complex::Complex; |
| 10 | |
| 11 | use super::assert_approx_eq; |
| 12 | |
| 13 | /// Returns an H gate. |
| 14 | fn noiseless_h() -> Operation { |
| 15 | let f = 0.5_f64.sqrt(); |
| 16 | operation!([f, f; |
| 17 | f, -f;]) |
| 18 | .expect("operation should be valid") |
| 19 | } |
| 20 | |
| 21 | /// Returns a CNOT gate. |
| 22 | fn noiseless_cnot() -> Operation { |
| 23 | operation!([1., 0., 0., 0.; |
| 24 | 0., 1., 0., 0.; |
| 25 | 0., 0., 0., 1.; |
| 26 | 0., 0., 1., 0.;]) |
| 27 | .expect("operation should be valid") |
| 28 | } |
| 29 | |
| 30 | /// Returns the 0-projection of an MZ measurement. |
| 31 | fn noiseless_mz0() -> Operation { |
| 32 | operation!([1., 0.; |
| 33 | 0., 0.;]) |
| 34 | .expect("operation should be valid") |
| 35 | } |
| 36 | |
| 37 | /// Returns the 1-projection of an MZ measurement. |
| 38 | fn noiseless_mz1() -> Operation { |
| 39 | operation!([0., 0.; |
| 40 | 0., 1.;]) |
| 41 | .expect("operation should be valid") |
| 42 | } |
| 43 | |
| 44 | /// Returns an MZ measurement. |
| 45 | pub(super) fn noiseless_mz() -> Instrument { |
| 46 | Instrument::new(vec![noiseless_mz0(), noiseless_mz1()]).expect("instrument should be valid") |
| 47 | } |
| 48 | |
| 49 | pub fn check_measuring_plus_state_yields_zero_with_50_percent_probability<NS: NoisySimulator>() { |
| 50 | let h = noiseless_h(); |
| 51 | let mz = noiseless_mz(); |
| 52 | let mut sim = NS::new(1); |
| 53 | sim.apply_operation(&h, &[0]) |
| 54 | .expect("operation should succeed"); |
| 55 | |
| 56 | // Random samples less than 0.5 should yield a 0-measurement. |
| 57 | let measurement = sim |
| 58 | .sample_instrument_with_distribution(&mz, &[0], 0.49999) |
| 59 | .expect("measurement should succeed"); |
| 60 | assert_eq!(measurement, 0); |
| 61 | } |
| 62 | |
| 63 | pub fn check_measuring_plus_state_yields_one_with_50_percent_probability<NS: NoisySimulator>() { |
| 64 | let h = noiseless_h(); |
| 65 | let mz = noiseless_mz(); |
| 66 | let mut sim = NS::new(1); |
| 67 | sim.apply_operation(&h, &[0]) |
| 68 | .expect("operation should succeed"); |
| 69 | |
| 70 | // Random samples greater than 0.5 should yield a 1-measurement. |
| 71 | let measurement = sim |
| 72 | .sample_instrument_with_distribution(&mz, &[0], 0.50001) |
| 73 | .expect("measurement should succeed"); |
| 74 | assert_eq!(measurement, 1); |
| 75 | } |
| 76 | |
| 77 | /// Check that both measurements in a Bell Pair yield the same result. |
| 78 | pub fn check_bell_pair_sampling_yields_same_outcome_for_both_qubits<NS: NoisySimulator>(seed: u64) { |
| 79 | let (h, cnot, mz) = (noiseless_h(), noiseless_cnot(), noiseless_mz()); |
| 80 | let mut sim = NS::new_with_seed(2, seed); |
| 81 | |
| 82 | // Make a Bell Pair. |
| 83 | sim.apply_operation(&h, &[0]) |
| 84 | .expect("operation should succeed"); |
| 85 | sim.apply_operation(&cnot, &[1, 0]) |
| 86 | .expect("operation should succeed"); |
| 87 | |
| 88 | // Measure both qubits. |
| 89 | let m1 = sim |
| 90 | .sample_instrument(&mz, &[0]) |
| 91 | .expect("measurement should succeed"); |
| 92 | let m2 = sim |
| 93 | .sample_instrument(&mz, &[1]) |
| 94 | .expect("measurement should succeed"); |
| 95 | |
| 96 | // Check that both measurements yield the same result. |
| 97 | assert_eq!(m1, m2); |
| 98 | } |
| 99 | |
| 100 | /// Project both qubits of a Bell Pair on the mz0 direction. |
| 101 | /// The trace of the system (i.e. the probability of finding |
| 102 | /// the quantum system in this state) should be 0.5. |
| 103 | pub fn check_bell_pair_projection_on_mz0_yields_50_percent_probability_trace<NS: NoisySimulator>() { |
| 104 | let (h, cnot, mz0) = (noiseless_h(), noiseless_cnot(), noiseless_mz0()); |
| 105 | let mut sim = NS::new(2); |
| 106 | |
| 107 | // Make a Bell Pair. |
| 108 | sim.apply_operation(&h, &[0]) |
| 109 | .expect("operation should succeed"); |
| 110 | sim.apply_operation(&cnot, &[1, 0]) |
| 111 | .expect("operation should succeed"); |
| 112 | |
| 113 | // Project both qubits on the mz0 direction. |
| 114 | sim.apply_operation(&mz0, &[0]) |
| 115 | .expect("operation should succeed"); |
| 116 | sim.apply_operation(&mz0, &[1]) |
| 117 | .expect("operation should succeed"); |
| 118 | assert_approx_eq(0.5, sim.trace_change().expect("state should be valid")); |
| 119 | |
| 120 | // Repeating the projection twice should yield the same result. |
| 121 | sim.apply_operation(&mz0, &[0]) |
| 122 | .expect("operation should succeed"); |
| 123 | sim.apply_operation(&mz0, &[1]) |
| 124 | .expect("operation should succeed"); |
| 125 | assert_approx_eq(0.5, sim.trace_change().expect("state should be valid")); |
| 126 | } |
| 127 | |
| 128 | /// Project both qubits of a Bell Pair on the mz1 direction. |
| 129 | /// The trace of the system (i.e. the probability of finding |
| 130 | /// the quantum system in this state) should be 0.5. |
| 131 | pub fn check_bell_pair_projection_on_mz1_yields_50_percent_probability_trace<NS: NoisySimulator>() { |
| 132 | let (h, cnot, mz1) = (noiseless_h(), noiseless_cnot(), noiseless_mz1()); |
| 133 | let mut sim = NS::new(2); |
| 134 | |
| 135 | // Make a Bell Pair. |
| 136 | sim.apply_operation(&h, &[0]) |
| 137 | .expect("operation should succeed"); |
| 138 | sim.apply_operation(&cnot, &[1, 0]) |
| 139 | .expect("operation should succeed"); |
| 140 | |
| 141 | // Project both qubits on the mz1 direction. |
| 142 | sim.apply_operation(&mz1, &[0]) |
| 143 | .expect("operation should succeed"); |
| 144 | sim.apply_operation(&mz1, &[1]) |
| 145 | .expect("operation should succeed"); |
| 146 | assert_approx_eq(0.5, sim.trace_change().expect("state should be valid")); |
| 147 | |
| 148 | // Repeating the projection twice should yield the same result. |
| 149 | sim.apply_operation(&mz1, &[0]) |
| 150 | .expect("operation should succeed"); |
| 151 | sim.apply_operation(&mz1, &[1]) |
| 152 | .expect("operation should succeed"); |
| 153 | assert_approx_eq(0.5, sim.trace_change().expect("state should be valid")); |
| 154 | } |
| 155 | |
| 156 | /// Project one qubit of a Bell Pair on the mz0 direction and the other on the mz1 direction. |
| 157 | /// This should yield a 0-probability error. |
| 158 | pub fn check_bell_pair_projection_on_oposite_directions_yields_an_error<NS: NoisySimulator>() { |
| 159 | let (h, cnot, mz0, mz1) = ( |
| 160 | noiseless_h(), |
| 161 | noiseless_cnot(), |
| 162 | noiseless_mz0(), |
| 163 | noiseless_mz1(), |
| 164 | ); |
| 165 | let mut sim = NS::new(2); |
| 166 | |
| 167 | // Make a Bell Pair. |
| 168 | sim.apply_operation(&h, &[0]) |
| 169 | .expect("operation should succeed"); |
| 170 | sim.apply_operation(&cnot, &[1, 0]) |
| 171 | .expect("operation should succeed"); |
| 172 | |
| 173 | // Project first qubit on the mz0 direction. |
| 174 | sim.apply_operation(&mz0, &[0]) |
| 175 | .expect("operation should succeed"); |
| 176 | |
| 177 | // Project second qubit on the mz1 direction. |
| 178 | // This should yield a 0-probability error. |
| 179 | sim.apply_operation(&mz1, &[1]) |
| 180 | .expect("operation should fail"); |
| 181 | } |
| 182 | |
| 183 | /// Check that projecting the target qubit in a CRX gate on the mz0 direction yields the right probabilities. |
| 184 | pub fn check_crx_gate_projection_on_mz0_yields_right_probabilities<NS: NoisySimulator>() { |
| 185 | let (h, mz0, mz1) = (noiseless_h(), noiseless_mz0(), noiseless_mz1()); |
| 186 | let probabilities: Vec<f64> = vec![0.05, 0.1, 0.3, 0.7, 0.8, 0.9, 0.99]; |
| 187 | |
| 188 | // A CRX gate (Controlled Rotation around X axis). |
| 189 | let crx = |t: f64| { |
| 190 | let c = t.cos(); |
| 191 | let s = t.sin() * Complex::I; |
| 192 | operation!([1., 0., 0., 0.; |
| 193 | 0., 1., 0., 0.; |
| 194 | 0., 0., c, s; |
| 195 | 0., 0., s, c;]) |
| 196 | .expect("operation should be valid") |
| 197 | }; |
| 198 | |
| 199 | for p in &probabilities { |
| 200 | let t = p.sqrt().acos(); |
| 201 | let mut sim = NS::new(2); |
| 202 | |
| 203 | // Apply CRX gate |
| 204 | sim.apply_operation(&h, &[0]) |
| 205 | .expect("operation should succeed"); |
| 206 | sim.apply_operation(&crx(0.3 * t), &[1, 0]) |
| 207 | .expect("operation should succeed"); |
| 208 | sim.apply_operation(&crx(0.7 * t), &[1, 0]) |
| 209 | .expect("operation should succeed"); |
| 210 | |
| 211 | sim.apply_operation(&mz1, &[0]) |
| 212 | .expect("operation should succeed"); |
| 213 | assert_approx_eq(0.5, sim.trace_change().expect("state should be valid")); |
| 214 | |
| 215 | // Project target qubit on mz0 and check the trace |
| 216 | // (the probability of finding the system in that state). |
| 217 | sim.apply_operation(&mz0, &[1]) |
| 218 | .expect("operation should succeed"); |
| 219 | assert_approx_eq(0.5 * *p, sim.trace_change().expect("state should be valid")); |
| 220 | |
| 221 | // Repeating a projection should yield the same result. |
| 222 | sim.apply_operation(&mz0, &[1]) |
| 223 | .expect("operation should succeed"); |
| 224 | assert_approx_eq(0.5 * *p, sim.trace_change().expect("state should be valid")); |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | /// Check that projecting the target qubit in a CRX gate on the mz1 direction yields the right probabilities. |
| 229 | pub fn check_crx_gate_projection_on_mz1_yields_right_probabilities<NS: NoisySimulator>() { |
| 230 | let (h, mz1) = (noiseless_h(), noiseless_mz1()); |
| 231 | let probabilities: Vec<f64> = vec![0.05, 0.1, 0.3, 0.7, 0.8, 0.9, 0.99]; |
| 232 | |
| 233 | // A CRX gate (Controlled Rotation around X axis). |
| 234 | let crx = |t: f64| { |
| 235 | let c = t.cos(); |
| 236 | let s = t.sin() * Complex::I; |
| 237 | operation!([1., 0., 0., 0.; |
| 238 | 0., 1., 0., 0.; |
| 239 | 0., 0., c, s; |
| 240 | 0., 0., s, c;]) |
| 241 | .expect("operation should be valid") |
| 242 | }; |
| 243 | |
| 244 | for p in &probabilities { |
| 245 | let t = p.sqrt().acos(); |
| 246 | let mut sim = NS::new(2); |
| 247 | |
| 248 | // Apply CRX gate |
| 249 | sim.apply_operation(&h, &[0]) |
| 250 | .expect("operation should succeed"); |
| 251 | sim.apply_operation(&crx(0.3 * t), &[1, 0]) |
| 252 | .expect("operation should succeed"); |
| 253 | sim.apply_operation(&crx(0.7 * t), &[1, 0]) |
| 254 | .expect("operation should succeed"); |
| 255 | |
| 256 | sim.apply_operation(&mz1, &[0]) |
| 257 | .expect("operation should succeed"); |
| 258 | assert_approx_eq(0.5, sim.trace_change().expect("state should be valid")); |
| 259 | |
| 260 | // Project target qubit on mz1 and check the trace |
| 261 | // (the probability of finding the system in that state). |
| 262 | sim.apply_operation(&mz1, &[1]) |
| 263 | .expect("operation should succeed"); |
| 264 | assert_approx_eq( |
| 265 | 0.5 * (1. - *p), |
| 266 | sim.trace_change().expect("state should be valid"), |
| 267 | ); |
| 268 | |
| 269 | // Repeating a projection should yield the same result. |
| 270 | sim.apply_operation(&mz1, &[1]) |
| 271 | .expect("operation should succeed"); |
| 272 | assert_approx_eq( |
| 273 | 0.5 * (1. - *p), |
| 274 | sim.trace_change().expect("state should be valid"), |
| 275 | ); |
| 276 | } |
| 277 | } |
| 278 | |
| 279 | /// Check that two consecutive MZ on the same qubit yield the same outcome. |
| 280 | pub fn check_two_consecutive_mz_yield_same_outcome<NS: NoisySimulator>(seed: u64) { |
| 281 | let h = noiseless_h(); |
| 282 | let mz = noiseless_mz(); |
| 283 | let mut sim = NS::new_with_seed(1, seed); |
| 284 | |
| 285 | sim.apply_operation(&h, &[0]) |
| 286 | .expect("operation should succeed"); |
| 287 | let outcome_0 = sim |
| 288 | .sample_instrument(&mz, &[0]) |
| 289 | .expect("measurement should succeed"); |
| 290 | let outcome_1 = sim |
| 291 | .sample_instrument(&mz, &[0]) |
| 292 | .expect("measurement should succeed"); |
| 293 | assert_eq!(outcome_0, outcome_1); |
| 294 | } |
| 295 | |
| 296 | pub fn check_alternating_mz_and_mx_yield_right_probabilities<NS: NoisySimulator>() { |
| 297 | let h = noiseless_h(); |
| 298 | let mz = noiseless_mz(); |
| 299 | let mx = Instrument::new(vec![ |
| 300 | operation!([0.5, 0.5; |
| 301 | 0.5, 0.5;]) |
| 302 | .expect("operation should be valid"), |
| 303 | operation!([ 0.5, -0.5; |
| 304 | -0.5, 0.5;]) |
| 305 | .expect("operation should be valid"), |
| 306 | ]) |
| 307 | .expect("instrument should be valid"); |
| 308 | |
| 309 | let mut sim = NS::new(1); |
| 310 | sim.apply_operation(&h, &[0]) |
| 311 | .expect("operation should succeed"); |
| 312 | let mut prob = 1.0; |
| 313 | |
| 314 | // Alternate MZ and MX 5 times. |
| 315 | for _ in 0..5 { |
| 316 | sim.sample_instrument(&mz, &[0]) |
| 317 | .expect("measurement should succeed"); |
| 318 | prob *= 0.5; |
| 319 | assert_approx_eq(prob, sim.trace_change().expect("state should be valid")); |
| 320 | sim.sample_instrument(&mx, &[0]) |
| 321 | .expect("measurement should succeed"); |
| 322 | prob *= 0.5; |
| 323 | assert_approx_eq(prob, sim.trace_change().expect("state should be valid")); |
| 324 | } |
| 325 | } |
| 326 | |