microsoft/qdk
Publicmirrored fromhttps://github.com/microsoft/qdkAvailable
library/std/src/Std/Canon.qs
826lines · modecode
| 1 | // Copyright (c) Microsoft Corporation. |
| 2 | // Licensed under the MIT License. |
| 3 | |
| 4 | |
| 5 | import QIR.Intrinsic.*; |
| 6 | import Std.Intrinsic.*; |
| 7 | import Std.Diagnostics.*; |
| 8 | import Std.Math.*; |
| 9 | |
| 10 | /// # Summary |
| 11 | /// Applies an operation to each element in a register. |
| 12 | /// |
| 13 | /// # Input |
| 14 | /// ## singleElementOperation |
| 15 | /// Operation to apply to each element. |
| 16 | /// ## register |
| 17 | /// Array of elements on which to apply the given operation. |
| 18 | /// |
| 19 | /// # Type Parameters |
| 20 | /// ## 'T |
| 21 | /// The target on which the operation acts. |
| 22 | /// |
| 23 | /// # Example |
| 24 | /// Prepare a three-qubit |+⟩ state: |
| 25 | /// ```qsharp |
| 26 | /// use register = Qubit[3]; |
| 27 | /// ApplyToEach(H, register); |
| 28 | /// ``` |
| 29 | operation ApplyToEach<'T>(singleElementOperation : ('T => Unit), register : 'T[]) : Unit { |
| 30 | for item in register { |
| 31 | singleElementOperation(item); |
| 32 | } |
| 33 | } |
| 34 | |
| 35 | /// # Summary |
| 36 | /// Applies an operation to each element in a register. |
| 37 | /// The modifier `A` indicates that the single-element operation is adjointable. |
| 38 | /// |
| 39 | /// # Input |
| 40 | /// ## singleElementOperation |
| 41 | /// Operation to apply to each element. |
| 42 | /// ## register |
| 43 | /// Array of elements on which to apply the given operation. |
| 44 | /// |
| 45 | /// # Type Parameters |
| 46 | /// ## 'T |
| 47 | /// The target on which the operation acts. |
| 48 | /// |
| 49 | /// # Example |
| 50 | /// Prepare a three-qubit |+⟩ state: |
| 51 | /// ```qsharp |
| 52 | /// use register = Qubit[3]; |
| 53 | /// ApplyToEach(H, register); |
| 54 | /// ``` |
| 55 | /// |
| 56 | /// # See Also |
| 57 | /// - [Std.Canon.ApplyToEach](xref:Qdk.Std.Canon.ApplyToEach) |
| 58 | operation ApplyToEachA<'T>(singleElementOperation : ('T => Unit is Adj), register : 'T[]) : Unit is Adj { |
| 59 | for item in register { |
| 60 | singleElementOperation(item); |
| 61 | } |
| 62 | } |
| 63 | |
| 64 | /// # Summary |
| 65 | /// Applies an operation to each element in a register. |
| 66 | /// The modifier `C` indicates that the single-element operation is controllable. |
| 67 | /// |
| 68 | /// # Input |
| 69 | /// ## singleElementOperation |
| 70 | /// Operation to apply to each element. |
| 71 | /// ## register |
| 72 | /// Array of elements on which to apply the given operation. |
| 73 | /// |
| 74 | /// # Type Parameters |
| 75 | /// ## 'T |
| 76 | /// The target on which the operation acts. |
| 77 | /// |
| 78 | /// # Example |
| 79 | /// Prepare a three-qubit |+⟩ state: |
| 80 | /// ```qsharp |
| 81 | /// use register = Qubit[3]; |
| 82 | /// ApplyToEach(H, register); |
| 83 | /// ``` |
| 84 | /// |
| 85 | /// # See Also |
| 86 | /// - [Std.Canon.ApplyToEach](xref:Qdk.Std.Canon.ApplyToEach) |
| 87 | operation ApplyToEachC<'T>(singleElementOperation : ('T => Unit is Ctl), register : 'T[]) : Unit is Ctl { |
| 88 | for item in register { |
| 89 | singleElementOperation(item); |
| 90 | } |
| 91 | } |
| 92 | |
| 93 | /// # Summary |
| 94 | /// Applies an operation to each element in a register. |
| 95 | /// The modifier `CA` indicates that the single-element operation is controllable and adjointable. |
| 96 | /// |
| 97 | /// # Input |
| 98 | /// ## singleElementOperation |
| 99 | /// Operation to apply to each element. |
| 100 | /// ## register |
| 101 | /// Array of elements on which to apply the given operation. |
| 102 | /// |
| 103 | /// # Type Parameters |
| 104 | /// ## 'T |
| 105 | /// The target on which the operation acts. |
| 106 | /// |
| 107 | /// # Example |
| 108 | /// Prepare a three-qubit |+⟩ state: |
| 109 | /// ```qsharp |
| 110 | /// use register = Qubit[3]; |
| 111 | /// ApplyToEach(H, register); |
| 112 | /// ``` |
| 113 | /// |
| 114 | /// # See Also |
| 115 | /// - [Std.Canon.ApplyToEach](xref:Qdk.Std.Canon.ApplyToEach) |
| 116 | operation ApplyToEachCA<'T>(singleElementOperation : ('T => Unit is Adj + Ctl), register : 'T[]) : Unit is Adj + Ctl { |
| 117 | for item in register { |
| 118 | singleElementOperation(item); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | /// # Summary |
| 123 | /// Applies the controlled-X (CX) gate to a pair of qubits. |
| 124 | /// |
| 125 | /// # Input |
| 126 | /// ## control |
| 127 | /// Control qubit for the CX gate. |
| 128 | /// ## target |
| 129 | /// Target qubit for the CX gate. |
| 130 | /// |
| 131 | /// # Remarks |
| 132 | /// This operation can be simulated by the unitary matrix |
| 133 | /// $$ |
| 134 | /// \begin{align} |
| 135 | /// \left(\begin{matrix} |
| 136 | /// 1 & 0 & 0 & 0 \\\\ |
| 137 | /// 0 & 1 & 0 & 0 \\\\ |
| 138 | /// 0 & 0 & 0 & 1 \\\\ |
| 139 | /// 0 & 0 & 1 & 0 |
| 140 | /// \end{matrix}\right) |
| 141 | /// \end{align}, |
| 142 | /// $$ |
| 143 | /// where rows and columns are organized as in the quantum concepts guide. |
| 144 | /// |
| 145 | /// Equivalent to: |
| 146 | /// ```qsharp |
| 147 | /// Controlled X([control], target); |
| 148 | /// ``` |
| 149 | /// and to: |
| 150 | /// ```qsharp |
| 151 | /// CNOT(control, target); |
| 152 | /// ``` |
| 153 | operation CX(control : Qubit, target : Qubit) : Unit is Adj + Ctl { |
| 154 | body ... { |
| 155 | __quantum__qis__cx__body(control, target); |
| 156 | } |
| 157 | controlled (ctls, ...) { |
| 158 | Controlled X(ctls + [control], target); |
| 159 | } |
| 160 | adjoint self; |
| 161 | } |
| 162 | |
| 163 | /// # Summary |
| 164 | /// Applies the controlled-Y (CY) gate to a pair of qubits. |
| 165 | /// |
| 166 | /// # Input |
| 167 | /// ## control |
| 168 | /// Control qubit for the CY gate. |
| 169 | /// ## target |
| 170 | /// Target qubit for the CY gate. |
| 171 | /// |
| 172 | /// # Remarks |
| 173 | /// This operation can be simulated by the unitary matrix |
| 174 | /// $$ |
| 175 | /// \begin{align} |
| 176 | /// \left(\begin{matrix} |
| 177 | /// 1 & 0 & 0 & 0 \\\\ |
| 178 | /// 0 & 1 & 0 & 0 \\\\ |
| 179 | /// 0 & 0 & 0 & -i \\\\ |
| 180 | /// 0 & 0 & i & 0 |
| 181 | /// \end{matrix}\right) |
| 182 | /// \end{align}, |
| 183 | /// $$ |
| 184 | /// where rows and columns are organized as in the quantum concepts guide. |
| 185 | /// |
| 186 | /// Equivalent to: |
| 187 | /// ```qsharp |
| 188 | /// Controlled Y([control], target); |
| 189 | /// ``` |
| 190 | operation CY(control : Qubit, target : Qubit) : Unit is Adj + Ctl { |
| 191 | body ... { |
| 192 | __quantum__qis__cy__body(control, target); |
| 193 | } |
| 194 | controlled (ctls, ...) { |
| 195 | Controlled Y(ctls + [control], target); |
| 196 | } |
| 197 | adjoint self; |
| 198 | } |
| 199 | |
| 200 | /// # Summary |
| 201 | /// Applies the controlled-Z (CZ) gate to a pair of qubits. |
| 202 | /// |
| 203 | /// # Input |
| 204 | /// ## control |
| 205 | /// Control qubit for the CZ gate. |
| 206 | /// ## target |
| 207 | /// Target qubit for the CZ gate. |
| 208 | /// |
| 209 | /// # Remarks |
| 210 | /// This operation can be simulated by the unitary matrix |
| 211 | /// $$ |
| 212 | /// \begin{align} |
| 213 | /// \left(\begin{matrix} |
| 214 | /// 1 & 0 & 0 & 0 \\\\ |
| 215 | /// 0 & 1 & 0 & 0 \\\\ |
| 216 | /// 0 & 0 & 1 & 0 \\\\ |
| 217 | /// 0 & 0 & 0 & -1 |
| 218 | /// \end{matrix}\right) |
| 219 | /// \end{align}, |
| 220 | /// $$ |
| 221 | /// where rows and columns are organized as in the quantum concepts guide. |
| 222 | /// |
| 223 | /// Equivalent to: |
| 224 | /// ```qsharp |
| 225 | /// Controlled Z([control], target); |
| 226 | /// ``` |
| 227 | operation CZ(control : Qubit, target : Qubit) : Unit is Adj + Ctl { |
| 228 | body ... { |
| 229 | __quantum__qis__cz__body(control, target); |
| 230 | } |
| 231 | controlled (ctls, ...) { |
| 232 | Controlled Z(ctls + [control], target); |
| 233 | } |
| 234 | adjoint self; |
| 235 | } |
| 236 | |
| 237 | /// Given a pair, returns its first element. |
| 238 | function Fst<'T, 'U>(pair : ('T, 'U)) : 'T { |
| 239 | let (fst, _) = pair; |
| 240 | return fst; |
| 241 | } |
| 242 | |
| 243 | /// Given a pair, returns its second element. |
| 244 | function Snd<'T, 'U>(pair : ('T, 'U)) : 'U { |
| 245 | let (_, snd) = pair; |
| 246 | return snd; |
| 247 | } |
| 248 | |
| 249 | /// # Summary |
| 250 | /// Computes the parity of a register of qubits in-place. |
| 251 | /// |
| 252 | /// # Input |
| 253 | /// ## qubits |
| 254 | /// Array of qubits whose parity is to be computed and stored. |
| 255 | /// |
| 256 | /// # Remarks |
| 257 | /// This operation transforms the state of its input as |
| 258 | /// $$ |
| 259 | /// \begin{align} |
| 260 | /// \ket{q_0} \ket{q_1} \cdots \ket{q_{n - 1}} & \mapsto |
| 261 | /// \ket{q_0} \ket{q_0 \oplus q_1} \ket{q_0 \oplus q_1 \oplus q_2} \cdots |
| 262 | /// \ket{q_0 \oplus \cdots \oplus q_{n - 1}}. |
| 263 | /// \end{align} |
| 264 | /// $$ |
| 265 | operation ApplyCNOTChain(qubits : Qubit[]) : Unit is Adj + Ctl { |
| 266 | for i in 0..Length(qubits) - 2 { |
| 267 | CNOT(qubits[i], qubits[i + 1]); |
| 268 | } |
| 269 | } |
| 270 | |
| 271 | /// # Summary |
| 272 | /// Given a single-qubit Pauli operator, applies the corresponding operation |
| 273 | /// to a single qubit. |
| 274 | /// |
| 275 | /// # Input |
| 276 | /// ## pauli |
| 277 | /// The Pauli operator to be applied. |
| 278 | /// ## target |
| 279 | /// The qubit to which `pauli` is to be applied as an operation. |
| 280 | /// |
| 281 | /// # Example |
| 282 | /// The following are equivalent: |
| 283 | /// ```qsharp |
| 284 | /// ApplyP(PauliX, q); |
| 285 | /// ``` |
| 286 | /// and |
| 287 | /// ```qsharp |
| 288 | /// X(q); |
| 289 | /// ``` |
| 290 | operation ApplyP(pauli : Pauli, target : Qubit) : Unit is Adj + Ctl { |
| 291 | if pauli == PauliX { X(target); } elif pauli == PauliY { Y(target); } elif pauli == PauliZ { Z(target); } |
| 292 | } |
| 293 | |
| 294 | /// # Summary |
| 295 | /// Given a multi-qubit Pauli operator, applies the corresponding operation |
| 296 | /// to a quantum register. |
| 297 | /// |
| 298 | /// # Input |
| 299 | /// ## pauli |
| 300 | /// A multi-qubit Pauli operator represented as an array of single-qubit Pauli operators. |
| 301 | /// ## target |
| 302 | /// Register to apply the given Pauli operation on. |
| 303 | /// |
| 304 | /// # Example |
| 305 | /// The following are equivalent: |
| 306 | /// ```qsharp |
| 307 | /// ApplyPauli([PauliY, PauliZ, PauliX], target); |
| 308 | /// ``` |
| 309 | /// and |
| 310 | /// ```qsharp |
| 311 | /// Y(target[0]); |
| 312 | /// Z(target[1]); |
| 313 | /// X(target[2]); |
| 314 | /// ``` |
| 315 | operation ApplyPauli(pauli : Pauli[], target : Qubit[]) : Unit is Adj + Ctl { |
| 316 | Fact(Length(pauli) == Length(target), "`pauli` and `target` must be of the same length."); |
| 317 | for i in 0..Length(pauli) - 1 { |
| 318 | ApplyP(pauli[i], target[i]); |
| 319 | } |
| 320 | } |
| 321 | |
| 322 | /// # Summary |
| 323 | /// Applies a Pauli operator on each qubit in an array if the corresponding |
| 324 | /// bit of a Boolean array matches a given input. |
| 325 | /// |
| 326 | /// # Input |
| 327 | /// ## pauli |
| 328 | /// Pauli operator to apply to `qubits[idx]` where `bitApply == bits[idx]` |
| 329 | /// ## bitApply |
| 330 | /// apply Pauli if bit is this value |
| 331 | /// ## bits |
| 332 | /// Boolean register specifying which corresponding qubit in `qubits` should be operated on |
| 333 | /// ## qubits |
| 334 | /// Quantum register on which to selectively apply the specified Pauli operator |
| 335 | /// |
| 336 | /// # Remarks |
| 337 | /// The Boolean array and the quantum register must be of equal length. |
| 338 | /// |
| 339 | /// # Example |
| 340 | /// The following applies an X operation on qubits 0 and 2, and a Z operation on qubits 1 and 3. |
| 341 | /// ```qsharp |
| 342 | /// use qubits = Qubit[4]; |
| 343 | /// let bits = [true, false, true, false]; |
| 344 | /// // Apply when index in `bits` is `true`. |
| 345 | /// ApplyPauliFromBitString(PauliX, true, bits, qubits); |
| 346 | /// // Apply when index in `bits` is `false`. |
| 347 | /// ApplyPauliFromBitString(PauliZ, false, bits, qubits); |
| 348 | /// ``` |
| 349 | operation ApplyPauliFromBitString(pauli : Pauli, bitApply : Bool, bits : Bool[], qubits : Qubit[]) : Unit is Adj + Ctl { |
| 350 | let nBits = Length(bits); |
| 351 | Fact(nBits == Length(qubits), "Number of bits must be equal to number of qubits."); |
| 352 | for i in 0..nBits - 1 { |
| 353 | if bits[i] == bitApply { |
| 354 | ApplyP(pauli, qubits[i]); |
| 355 | } |
| 356 | } |
| 357 | } |
| 358 | |
| 359 | /// # Summary |
| 360 | /// Applies a Pauli operator on each qubit in an array if the corresponding |
| 361 | /// bit of a Little-endian integer matches a given input. |
| 362 | /// |
| 363 | /// # Input |
| 364 | /// ## pauli |
| 365 | /// Pauli operator to apply to `qubits[idx]` when bit of numberState |
| 366 | /// in idx position is the same as bitApply. |
| 367 | /// ## bitApply |
| 368 | /// apply Pauli if bit is this value |
| 369 | /// ## numberState |
| 370 | /// Little-endian integer specifying which corresponding qubit in `qubits` should be operated on |
| 371 | /// ## qubits |
| 372 | /// Quantum register on which to selectively apply the specified Pauli operator |
| 373 | /// |
| 374 | /// # Example |
| 375 | /// The following applies an X operation on qubits 0 and 2, and a Z operation on qubits 1 and 3. |
| 376 | /// ```qsharp |
| 377 | /// use qubits = Qubit[4]; |
| 378 | /// let n = 5; |
| 379 | /// // Apply when index in `bits` is `true`. |
| 380 | /// ApplyPauliFromBitString(PauliX, true, n, qubits); |
| 381 | /// // Apply when index in `bits` is `false`. |
| 382 | /// ApplyPauliFromBitString(PauliZ, false, n, qubits); |
| 383 | /// ``` |
| 384 | operation ApplyPauliFromInt( |
| 385 | pauli : Pauli, |
| 386 | bitApply : Bool, |
| 387 | numberState : Int, |
| 388 | qubits : Qubit[] |
| 389 | ) : Unit is Adj + Ctl { |
| 390 | |
| 391 | let length = Length(qubits); |
| 392 | Fact(numberState >= 0, "number must be non-negative"); |
| 393 | Fact(BitSizeI(numberState) <= length, "Bit size of numberState must not exceed qubits length"); |
| 394 | |
| 395 | for i in 0..length - 1 { |
| 396 | // If we assume loop unrolling, 2^i will be optimized to a constant. |
| 397 | if ((numberState &&& (1 <<< i)) != 0) == bitApply { |
| 398 | ApplyP(pauli, qubits[i]); |
| 399 | } |
| 400 | } |
| 401 | } |
| 402 | |
| 403 | /// # Summary |
| 404 | /// Maps a Pauli axis from one direction to another by applying an appropriate Clifford transformation. |
| 405 | /// For example, use `within MapPauliAxis(PauliZ, PauliX, q)` and perform Z rotation when X rotation is desired. |
| 406 | /// |
| 407 | /// # Description |
| 408 | /// This function applies single-qubit Clifford transformations that remap Pauli axes on a Bloch sphere. |
| 409 | /// These mappings are useful to apply operations known for one Pauli basis in different Pauli bases. |
| 410 | /// Provide `from` and `to` parameters in terms of a passive transformation. For example, |
| 411 | /// when a rotation around the X axis is desired and a rotation around the Z axis is available, |
| 412 | /// the Z axis gets pointed in the direction of the X axis so that the rotation around Z axis can be used. |
| 413 | /// Out of several transformations that achieve the requested mapping, the one with fewer gates is used. |
| 414 | /// |
| 415 | /// # Input |
| 416 | /// ## from |
| 417 | /// The Pauli axis to map from. Perform subsequent operations on this axis. |
| 418 | /// ## to |
| 419 | /// The Pauli axis to map to. Subsequent operations on `from` axis will perform as if they act on this axis. |
| 420 | /// ## q |
| 421 | /// The qubit on which the transformation will be applied. |
| 422 | /// |
| 423 | /// # Remarks |
| 424 | /// The complete list of possible mappings and a list of gate sequences to achieve them. |
| 425 | /// For example, a transformation of +X+Y+Z ↦ +X+Z-Y means that the bloch sphere is rotated so that |
| 426 | /// the X axis remains unchanged, Y axis points in Z direction, and Z axis points in -Y direction. |
| 427 | /// (Y with direction reversed). Such transformation could be used to achieve PauliZ to PauliY mapping. |
| 428 | /// |
| 429 | /// +X+Y+Z ↦ +X+Y+Z: I (used when `from` == `to`) \ |
| 430 | /// +X+Y+Z ↦ +Z-Y+X: H (used when mapping Z to X and X to Z) \ |
| 431 | /// +X+Y+Z ↦ +Y+Z+X: S⁻¹H (used when mapping Z to Y) \ |
| 432 | /// +X+Y+Z ↦ +Z+X+Y: HS (used when mapping Y to Z) \ |
| 433 | /// +X+Y+Z ↦ +Y-X+Z: S (used when mapping Y to X) \ |
| 434 | /// +X+Y+Z ↦ -Y+X+Z: S⁻¹ (used when mapping X to Y) \ |
| 435 | /// +X+Y+Z ↦ -X+Z+Y: S⁻¹HS \ |
| 436 | /// +X+Y+Z ↦ -Y-Z+X: SH \ |
| 437 | /// +X+Y+Z ↦ +Y-Z-X: SHZ, S⁻¹HY, YSH, SXH, S⁻¹YH, XS⁻¹H \ |
| 438 | /// +X+Y+Z ↦ -X-Z-Y: SHS⁻¹ \ |
| 439 | /// +X+Y+Z ↦ +X-Y-Z: X \ |
| 440 | /// +X+Y+Z ↦ -Z+X-Y: HXS⁻¹, HSX, ZHS⁻¹, YHS, HYS, HS⁻¹Y \ |
| 441 | /// +X+Y+Z ↦ +X-Z+Y: SHS, HS⁻¹H \ |
| 442 | /// +X+Y+Z ↦ -Y+Z-X: SHY, S⁻¹HZ, YS⁻¹H, SYH, S⁻¹XH, XSH \ |
| 443 | /// +X+Y+Z ↦ -X+Y-Z: Y \ |
| 444 | /// +X+Y+Z ↦ -Z+Y+X: HX, ZH \ |
| 445 | /// +X+Y+Z ↦ -Y-X-Z: YS, SX, S⁻¹Y, XS⁻¹ \ |
| 446 | /// +X+Y+Z ↦ +Y+X-Z: YS⁻¹, SY, S⁻¹X, XS \ |
| 447 | /// +X+Y+Z ↦ +Z+Y-X: XH, HZ \ |
| 448 | /// +X+Y+Z ↦ +X+Z-Y: S⁻¹HS⁻¹, HSH \ |
| 449 | /// +X+Y+Z ↦ -Z-X+Y: HXS, HSY, ZHS, YHS⁻¹, HYS⁻¹, HS⁻¹X \ |
| 450 | /// +X+Y+Z ↦ -X-Y+Z: Z \ |
| 451 | /// +X+Y+Z ↦ -Z-Y-X: YH, HY \ |
| 452 | /// +X+Y+Z ↦ +Z-X-Y: HS⁻¹ |
| 453 | /// |
| 454 | /// # Example |
| 455 | /// ```qsharp |
| 456 | /// // The following implements Rx(0.1, q) via Rz. |
| 457 | /// within { |
| 458 | /// MapPauliAxis(PauliZ, PauliX, q); |
| 459 | /// } apply { |
| 460 | /// Rz(0.1, q); |
| 461 | /// } |
| 462 | /// ``` |
| 463 | /// |
| 464 | /// # References |
| 465 | /// - [Wikipedia: Bloch sphere](https://wikipedia.org/wiki/Bloch_sphere) |
| 466 | /// - [Wikipedia: Clifford group](https://wikipedia.org/wiki/Clifford_group) |
| 467 | /// - [Wikipedia: Active and passive transformation](https://wikipedia.org/wiki/Active_and_passive_transformation) |
| 468 | operation MapPauliAxis(from : Pauli, to : Pauli, q : Qubit) : Unit is Adj + Ctl { |
| 469 | if from == to { |
| 470 | // +X+Y+Z ↦ +X+Y+Z, No gates are needed. |
| 471 | } elif (from == PauliZ and to == PauliX) or (from == PauliX and to == PauliZ) { |
| 472 | // +X+Y+Z ↦ +Z-Y+X |
| 473 | H(q); |
| 474 | } elif from == PauliZ and to == PauliY { |
| 475 | // +X+Y+Z ↦ +Y+Z+X |
| 476 | Adjoint S(q); |
| 477 | H(q); |
| 478 | } elif from == PauliY and to == PauliZ { |
| 479 | // +X+Y+Z ↦ +Z+X+Y |
| 480 | H(q); |
| 481 | S(q); |
| 482 | } elif from == PauliY and to == PauliX { |
| 483 | // +X+Y+Z ↦ +Y-X+Z |
| 484 | S(q); |
| 485 | } elif from == PauliX and to == PauliY { |
| 486 | // +X+Y+Z ↦ -Y+X+Z |
| 487 | Adjoint S(q); |
| 488 | } else { |
| 489 | fail "Unsupported mapping of Pauli axes."; |
| 490 | } |
| 491 | } |
| 492 | |
| 493 | /// # Summary |
| 494 | /// Applies a unitary operation on the target if the control |
| 495 | /// register state corresponds to a specified nonnegative integer. |
| 496 | /// |
| 497 | /// # Input |
| 498 | /// ## numberState |
| 499 | /// A nonnegative integer on which the operation `oracle` should be |
| 500 | /// controlled. |
| 501 | /// ## oracle |
| 502 | /// A unitary operation to be controlled. |
| 503 | /// ## target |
| 504 | /// A target on which to apply `oracle`. |
| 505 | /// ## controlRegister |
| 506 | /// A quantum register that controls application of `oracle`. |
| 507 | /// |
| 508 | /// # Remarks |
| 509 | /// The value of `numberState` is interpreted using a little-endian encoding. |
| 510 | /// |
| 511 | /// `numberState` must be at most $2^\texttt{Length(controlRegister)} - 1$. |
| 512 | /// For example, `numberState = 537` means that `oracle` |
| 513 | /// is applied if and only if `controlRegister` is in the state $\ket{537}$. |
| 514 | operation ApplyControlledOnInt<'T>( |
| 515 | numberState : Int, |
| 516 | oracle : ('T => Unit is Adj + Ctl), |
| 517 | controlRegister : Qubit[], |
| 518 | target : 'T |
| 519 | ) : Unit is Adj + Ctl { |
| 520 | |
| 521 | within { |
| 522 | ApplyPauliFromInt(PauliX, false, numberState, controlRegister); |
| 523 | } apply { |
| 524 | Controlled oracle(controlRegister, target); |
| 525 | } |
| 526 | } |
| 527 | |
| 528 | /// # Summary |
| 529 | /// Applies `oracle` on `target` when `controlRegister` |
| 530 | /// is in the state specified by `bits`. |
| 531 | /// |
| 532 | /// # Description |
| 533 | /// Applies a unitary operation `oracle` on the `target`, controlled |
| 534 | /// on a state specified by a given bit mask `bits`. |
| 535 | /// The bit at `bits[i]` corresponds to qubit at `controlRegister[i]`. |
| 536 | /// The pattern given by `bits` may be shorter than `controlRegister`, |
| 537 | /// in which case additional control qubits are ignored (that is, neither |
| 538 | /// controlled on |0⟩ nor |1⟩). |
| 539 | /// If `bits` is longer than `controlRegister`, an error is raised. |
| 540 | /// |
| 541 | /// # Input |
| 542 | /// ## bits |
| 543 | /// The bit string to control the given unitary operation on. |
| 544 | /// ## oracle |
| 545 | /// The unitary operation to be applied on the target. |
| 546 | /// ## target |
| 547 | /// The target to be passed to `oracle` as an input. |
| 548 | /// ## controlRegister |
| 549 | /// A quantum register that controls application of `oracle`. |
| 550 | /// |
| 551 | /// # Example |
| 552 | /// ```qsharp |
| 553 | /// // When bits = [1,0,0] oracle is applied if and only if controlRegister |
| 554 | /// // is in the state |100⟩. |
| 555 | /// use t = Qubit(); |
| 556 | /// use c = Qubit[3]; |
| 557 | /// X(c[0]); |
| 558 | /// ApplyControlledOnBitString([true, false, false], X, c, t); |
| 559 | /// Message($"{M(t)}"); // Prints `One` since oracle `X` was applied. |
| 560 | /// ``` |
| 561 | operation ApplyControlledOnBitString<'T>( |
| 562 | bits : Bool[], |
| 563 | oracle : ('T => Unit is Adj + Ctl), |
| 564 | controlRegister : Qubit[], |
| 565 | target : 'T |
| 566 | ) : Unit is Adj + Ctl { |
| 567 | |
| 568 | // The control register must have enough bits to implement the requested control. |
| 569 | Fact(Length(bits) <= Length(controlRegister), "Control register shorter than control pattern."); |
| 570 | |
| 571 | // Use a subregister of the controlled register when |
| 572 | // bits is shorter than controlRegister. |
| 573 | let controlSubregister = controlRegister[...Length(bits) - 1]; |
| 574 | within { |
| 575 | ApplyPauliFromBitString(PauliX, false, bits, controlSubregister); |
| 576 | } apply { |
| 577 | Controlled oracle(controlSubregister, target); |
| 578 | } |
| 579 | } |
| 580 | |
| 581 | /// # Summary |
| 582 | /// Applies the rotations of Quantum Fourier Transform (QFT) to a little-endian quantum register. |
| 583 | /// |
| 584 | /// # Description |
| 585 | /// Applies the rotations of QFT to a little-endian register `qs` of length n |
| 586 | /// containing |x₁⟩⊗|x₂⟩⊗…⊗|xₙ⟩. The qs[0] initially contains the |
| 587 | /// least significant bit xₙ. The state of qs[0] becomes |
| 588 | /// (|0⟩+𝑒^(2π𝑖[0.xₙ])|1⟩)/sqrt(2) after the operation. |
| 589 | /// |
| 590 | /// # Input |
| 591 | /// ## qs |
| 592 | /// Quantum register in a little-endian format to which the rotations are applied. |
| 593 | /// |
| 594 | /// # Remarks |
| 595 | /// Note that this operation applies only the rotations part of the QFT. |
| 596 | /// To complete the transform, you need to reverse the order of qubits after this operation, |
| 597 | /// for example, using the operation `SwapReverseRegister`. |
| 598 | /// |
| 599 | /// # Reference |
| 600 | /// - [Quantum Fourier transform](https://en.wikipedia.org/wiki/Quantum_Fourier_transform) |
| 601 | operation ApplyQFT(qs : Qubit[]) : Unit is Adj + Ctl { |
| 602 | let length = Length(qs); |
| 603 | Fact(length >= 1, "ApplyQFT: Length(qs) must be at least 1."); |
| 604 | for i in length - 1..-1..0 { |
| 605 | H(qs[i]); |
| 606 | for j in 0..i - 1 { |
| 607 | Controlled R1Frac([qs[i]], (1, j + 1, qs[i - j - 1])); |
| 608 | } |
| 609 | } |
| 610 | } |
| 611 | |
| 612 | /// # Summary |
| 613 | /// Uses SWAP gates to reverse the order of the qubits in a register. |
| 614 | /// |
| 615 | /// # Input |
| 616 | /// ## register |
| 617 | /// The qubits order of which should be reversed using SWAP gates |
| 618 | operation SwapReverseRegister(register : Qubit[]) : Unit is Adj + Ctl { |
| 619 | let length = Length(register); |
| 620 | for i in 0..length / 2 - 1 { |
| 621 | SWAP(register[i], register[(length - i) - 1]); |
| 622 | } |
| 623 | } |
| 624 | |
| 625 | /// # Summary |
| 626 | /// Applies a bitwise-XOR operation between a classical integer and an |
| 627 | /// integer represented by a register of qubits. |
| 628 | /// |
| 629 | /// # Description |
| 630 | /// Applies `X` operations to qubits in a little-endian register based on |
| 631 | /// 1 bits in an integer. |
| 632 | /// |
| 633 | /// Let us denote `value` by a and let y be an unsigned integer encoded in `target`, |
| 634 | /// then `ApplyXorInPlace` performs an operation given by the following map: |
| 635 | /// |y⟩ ↦ |y ⊕ a⟩, where ⊕ is the bitwise exclusive OR operator. |
| 636 | operation ApplyXorInPlace(value : Int, target : Qubit[]) : Unit is Adj + Ctl { |
| 637 | body (...) { |
| 638 | Fact(value >= 0, "`value` must be non-negative."); |
| 639 | mutable runningValue = value; |
| 640 | for q in target { |
| 641 | if (runningValue &&& 1) != 0 { |
| 642 | X(q); |
| 643 | } |
| 644 | set runningValue >>>= 1; |
| 645 | } |
| 646 | Fact(runningValue == 0, "value is too large"); |
| 647 | } |
| 648 | adjoint self; |
| 649 | } |
| 650 | |
| 651 | /// # Summary |
| 652 | /// Applies a bitwise-XOR operation between a classical integer and an |
| 653 | /// integer represented by a register of qubits. |
| 654 | /// |
| 655 | /// # Description |
| 656 | /// Applies `X` operations to qubits in a little-endian register based on |
| 657 | /// 1 bits in an integer. |
| 658 | /// |
| 659 | /// Let us denote `value` by a and let y be an unsigned integer encoded in `target`, |
| 660 | /// then `ApplyXorInPlace` performs an operation given by the following map: |
| 661 | /// |y⟩ ↦ |y ⊕ a⟩, where ⊕ is the bitwise exclusive OR operator. |
| 662 | operation ApplyXorInPlaceL(value : BigInt, target : Qubit[]) : Unit is Adj + Ctl { |
| 663 | body (...) { |
| 664 | Fact(value >= 0L, "`value` must be non-negative."); |
| 665 | mutable runningValue = value; |
| 666 | for q in target { |
| 667 | if (runningValue &&& 1L) != 0L { |
| 668 | X(q); |
| 669 | } |
| 670 | set runningValue >>>= 1; |
| 671 | } |
| 672 | Fact(runningValue == 0L, "`value` is too large."); |
| 673 | } |
| 674 | adjoint self; |
| 675 | } |
| 676 | |
| 677 | /// # Summary |
| 678 | /// Applies operation `op` to the `target` `power` times. |
| 679 | /// If `power` is negative, the adjoint of `op` is used. |
| 680 | /// If `power` is 0, the operation `op` is not applied. |
| 681 | operation ApplyOperationPowerA<'T>( |
| 682 | power : Int, |
| 683 | op : 'T => Unit is Adj, |
| 684 | target : 'T |
| 685 | ) : Unit is Adj { |
| 686 | let u = if power >= 0 { op } else { Adjoint op }; |
| 687 | for _ in 1..AbsI(power) { |
| 688 | u(target); |
| 689 | } |
| 690 | } |
| 691 | |
| 692 | /// # Summary |
| 693 | /// Applies operation `op` to the `target` `power` times. |
| 694 | /// If `power` is negative, the adjoint of `op` is used. |
| 695 | /// If `power` is 0, the operation `op` is not applied. |
| 696 | operation ApplyOperationPowerCA<'T>( |
| 697 | power : Int, |
| 698 | op : 'T => Unit is Ctl + Adj, |
| 699 | target : 'T |
| 700 | ) : Unit is Ctl + Adj { |
| 701 | let u = if power >= 0 { op } else { Adjoint op }; |
| 702 | for _ in 1..AbsI(power) { |
| 703 | u(target); |
| 704 | } |
| 705 | } |
| 706 | |
| 707 | /// # Summary |
| 708 | /// Performs the quantum phase estimation algorithm for a unitary U represented |
| 709 | /// by `applyPowerOfU`, and a `targetState`. Returns the phase estimation |
| 710 | /// in the range of [0, 2π) as a fraction of 2π in the little-endian register `phase`. |
| 711 | /// |
| 712 | /// # Input |
| 713 | /// ## applyPowerOfU |
| 714 | /// An oracle implementing Uᵐ for a unitary U and a given integer power m. |
| 715 | /// `ApplyOperationPowerCA(_, U, _)` can be used to implement this oracle, |
| 716 | /// if no better performing implementation is available. |
| 717 | /// ## targetState |
| 718 | /// A quantum register acted on by U. When this `targetState` is the eigenstate |
| 719 | /// of the operator U, the corresponding eigenvalue is estimated. |
| 720 | /// ## phase |
| 721 | /// A little-endian quantum register containing the phase estimation result. The phase is |
| 722 | /// a fraction of 2π represented in binary with q[0] containing 2π/2=π bit, q[1] containing 2π/4=π/2 bit, |
| 723 | /// q[2] containing 2π/8=π/4 bit, and so on. The length of the register indicates the desired precision. |
| 724 | /// The phase register is assumed to be in the state |0...0⟩ when the operation is invoked. |
| 725 | /// |
| 726 | /// # Remarks |
| 727 | /// All eigenvalues of a unitary operator are of magnitude 1 and therefore can be represented as |
| 728 | /// $e^{i\phi}$ for some $\phi \in [0, 2\pi)$. Finding the phase of an eigenvalue is therefore |
| 729 | /// equivalent to finding the eigenvalue itself. Passing the eigenvector as `targetState` |
| 730 | /// to the phase estimation operation allows finding the eigenvalue to the desired precision |
| 731 | /// determined by the length of the `phase` register. |
| 732 | /// |
| 733 | /// # Reference |
| 734 | /// - [Quantum phase estimation algorithm](https://wikipedia.org/wiki/Quantum_phase_estimation_algorithm) |
| 735 | /// |
| 736 | /// # See Also |
| 737 | /// - [Std.Canon.ApplyOperationPowerCA](xref:Qdk.Std.Canon.ApplyOperationPowerCA) |
| 738 | operation ApplyQPE( |
| 739 | applyPowerOfU : (Int, Qubit[]) => Unit is Adj + Ctl, |
| 740 | targetState : Qubit[], |
| 741 | phase : Qubit[] |
| 742 | ) : Unit is Adj + Ctl { |
| 743 | |
| 744 | let nQubits = Length(phase); |
| 745 | ApplyToEachCA(H, phase); |
| 746 | |
| 747 | for i in 0..nQubits - 1 { |
| 748 | let power = 2^((nQubits - i) - 1); |
| 749 | Controlled applyPowerOfU( |
| 750 | phase[i..i], |
| 751 | (power, targetState) |
| 752 | ); |
| 753 | } |
| 754 | |
| 755 | Adjoint ApplyQFT(phase); |
| 756 | } |
| 757 | |
| 758 | /// # Summary |
| 759 | /// Relabels the qubits in the `current` array with the qubits in the `updated` array. The `updated` array |
| 760 | /// must be a valid permutation of the `current` array. |
| 761 | /// |
| 762 | /// # Input |
| 763 | /// ## current |
| 764 | /// Array of qubits to be relabeled. |
| 765 | /// ## updated |
| 766 | /// Array of qubits with which to relabel the `current` array. |
| 767 | /// |
| 768 | /// # Remarks |
| 769 | /// This operation is useful when you need to relabel qubits in a way that does not incur any quantum operations. |
| 770 | /// Note that when compiling for execution on hardware with limited qubit connectivity, this operation |
| 771 | /// may not result in any changes to qubit adjacency and one or more `SWAP` gates may still be required. |
| 772 | /// |
| 773 | /// # Example |
| 774 | /// The following example demonstrates how to relabel qubits in a register: |
| 775 | /// ```qsharp |
| 776 | /// use qubits = Qubit[3]; |
| 777 | /// let newOrder = [qubits[2], qubits[0], qubits[1]]; |
| 778 | /// Relabel(qubits, newOrder); |
| 779 | /// ``` |
| 780 | /// After this operation, any use of `qubits[0]` will refer to the qubit that was originally `qubits[2]`, and so on. |
| 781 | /// To exchange the labels on two qubits, the virtual equivalent of a `SWAP` gate, you can use the following code: |
| 782 | /// ```qsharp |
| 783 | /// use (q0, q1) = (Qubit(), Qubit()); |
| 784 | /// Relabel([q0, q1], [q1, q0]); |
| 785 | /// ``` |
| 786 | /// Note that the adjoint of this operation effectively changes the order of arguments, such that |
| 787 | /// `Adjoint Relabel(qubits, newOrder)` is equivalent to `Relabel(newOrder, qubits)`. |
| 788 | operation Relabel(current : Qubit[], updated : Qubit[]) : Unit is Adj { |
| 789 | body ... { |
| 790 | PermuteLabels(current, updated); |
| 791 | } |
| 792 | adjoint ... { |
| 793 | PermuteLabels(updated, current); |
| 794 | } |
| 795 | } |
| 796 | |
| 797 | operation PermuteLabels(current : Qubit[], updated : Qubit[]) : Unit { |
| 798 | body intrinsic; |
| 799 | } |
| 800 | |
| 801 | export |
| 802 | ApplyToEach, |
| 803 | ApplyToEachA, |
| 804 | ApplyToEachC, |
| 805 | ApplyToEachCA, |
| 806 | CX, |
| 807 | CY, |
| 808 | CZ, |
| 809 | Fst, |
| 810 | Snd, |
| 811 | ApplyCNOTChain, |
| 812 | ApplyP, |
| 813 | ApplyPauli, |
| 814 | ApplyPauliFromBitString, |
| 815 | ApplyPauliFromInt, |
| 816 | MapPauliAxis, |
| 817 | ApplyControlledOnInt, |
| 818 | ApplyControlledOnBitString, |
| 819 | ApplyQFT, |
| 820 | ApplyQPE, |
| 821 | SwapReverseRegister, |
| 822 | ApplyXorInPlace, |
| 823 | ApplyXorInPlaceL, |
| 824 | ApplyOperationPowerA, |
| 825 | ApplyOperationPowerCA, |
| 826 | Relabel; |
| 827 | |