#include "QuEST_precision.h"

Data Structures
struct	Complex
	Represents one complex number. More...

struct	ComplexMatrix2
	Represents a 2x2 matrix of complex numbers. More...

struct	ComplexMatrix4
	Represents a 4x4 matrix of complex numbers. More...

struct	ComplexMatrixN
	Represents a general 2^N by 2^N matrix of complex numbers. More...

struct	DiagonalOp
	Represents a diagonal complex operator on the full Hilbert state of a `Qureg`. More...

struct	PauliHamil
	Represents a weighted sum of pauli products. More...

struct	QuESTEnv
	Information about the environment the program is running in. More...

struct	Qureg
	Represents a system of qubits. More...

struct	Vector
	Represents a 3-vector of real numbers. More...

Macros
#define	getStaticComplexMatrixN(numQubits, re, im)
	Creates a ComplexMatrixN struct which lives in the stack and so does not need freeing, but cannot be returned beyond the calling scope. More...

Enumerations
enum	pauliOpType { PAULI_I =0, PAULI_X =1, PAULI_Y =2, PAULI_Z =3 }
	Codes for specifying Pauli operators. More...

Functions
void	applyDiagonalOp (Qureg qureg, DiagonalOp op)
	Apply a diagonal complex operator, which is possibly non-unitary and non-Hermitian, on the entire `qureg`, More...

void	applyMatrix2 (Qureg qureg, int targetQubit, ComplexMatrix2 u)
	Apply a general 2-by-2 matrix, which may be non-unitary. More...

void	applyMatrix4 (Qureg qureg, int targetQubit1, int targetQubit2, ComplexMatrix4 u)
	Apply a general 4-by-4 matrix, which may be non-unitary. More...

void	applyMatrixN (Qureg qureg, int *targs, int numTargs, ComplexMatrixN u)
	Apply a general N-by-N matrix, which may be non-unitary, on any number of target qubits. More...

void	applyMultiControlledMatrixN (Qureg qureg, int ctrls, int numCtrls, int targs, int numTargs, ComplexMatrixN u)
	Apply a general N-by-N matrix, which may be non-unitary, with additional controlled qubits. More...

void	applyPauliHamil (Qureg inQureg, PauliHamil hamil, Qureg outQureg)
	Modifies `outQureg` to be the result of applying `PauliHamil` (a Hermitian but not necessarily unitary operator) to `inQureg`. More...

void	applyPauliSum (Qureg inQureg, enum pauliOpType allPauliCodes, qreal termCoeffs, int numSumTerms, Qureg outQureg)
	Modifies `outQureg` to be the result of applying the weighted sum of Pauli products (a Hermitian but not necessarily unitary operator) to `inQureg`. More...

void	applyTrotterCircuit (Qureg qureg, PauliHamil hamil, qreal time, int order, int reps)
	Applies a trotterisation of unitary evolution $\exp(-i \, \text{hamil} \, \text{time})$ to `qureg`. More...

qreal	calcDensityInnerProduct (Qureg rho1, Qureg rho2)
	Computes the Hilbert-Schmidt scalar product (which is equivalent to the Frobenius inner product of matrices) of two density matrices `rho1` and `rho2` of equivalent size. More...

Complex	calcExpecDiagonalOp (Qureg qureg, DiagonalOp op)
	Computes the expected value of the diagonal operator `op` for state `qureg`. More...

qreal	calcExpecPauliHamil (Qureg qureg, PauliHamil hamil, Qureg workspace)
	Computes the expected value of `qureg` under Hermitian operator `hamil`. More...

qreal	calcExpecPauliProd (Qureg qureg, int targetQubits, enum pauliOpType pauliCodes, int numTargets, Qureg workspace)
	Computes the expected value of a product of Pauli operators. More...

qreal	calcExpecPauliSum (Qureg qureg, enum pauliOpType allPauliCodes, qreal termCoeffs, int numSumTerms, Qureg workspace)
	Computes the expected value of a sum of products of Pauli operators. More...

qreal	calcFidelity (Qureg qureg, Qureg pureState)
	Calculates the fidelity of `qureg` (a statevector or density matrix) against a reference pure state (necessarily a statevector). More...

qreal	calcHilbertSchmidtDistance (Qureg a, Qureg b)
	Computes the Hilbert Schmidt distance between two density matrices `a` and `b`, defined as the Frobenius norm of the difference between them. More...

Complex	calcInnerProduct (Qureg bra, Qureg ket)
	Computes the inner product $\langle \text{bra} \| \text{ket} \rangle$ of two equal-size state vectors, given by. More...

qreal	calcProbOfOutcome (Qureg qureg, int measureQubit, int outcome)
	Gives the probability of a specified qubit being measured in the given outcome (0 or 1). More...

qreal	calcPurity (Qureg qureg)
	Calculates the purity of a density matrix, by the trace of the density matrix squared. More...

qreal	calcTotalProb (Qureg qureg)
	A debugging function which calculates the probability of the qubits in `qureg` being in any state, which should always be 1 for correctly normalised states (hence returning a real number). More...

void	clearRecordedQASM (Qureg qureg)
	Clear all QASM so far recorded. More...

void	cloneQureg (Qureg targetQureg, Qureg copyQureg)
	Set targetQureg to be a clone of copyQureg. More...

qreal	collapseToOutcome (Qureg qureg, int measureQubit, int outcome)
	Updates `qureg` to be consistent with measuring `measureQubit` in the given `outcome` (0 or 1), and returns the probability of such a measurement outcome. More...

void	compactUnitary (Qureg qureg, int targetQubit, Complex alpha, Complex beta)
	Apply a single-qubit unitary parameterised by two given complex scalars. More...

void	controlledCompactUnitary (Qureg qureg, int controlQubit, int targetQubit, Complex alpha, Complex beta)
	Apply a controlled unitary (single control, single target) parameterised by two given complex scalars. More...

void	controlledMultiQubitUnitary (Qureg qureg, int ctrl, int *targs, int numTargs, ComplexMatrixN u)
	Apply a general controlled multi-qubit unitary (including a global phase factor). More...

void	controlledNot (Qureg qureg, int controlQubit, int targetQubit)
	Apply the controlled not (single control, single target) gate, also known as the c-X, c-sigma-X, c-Pauli-X and c-bit-flip gate. More...

void	controlledPauliY (Qureg qureg, int controlQubit, int targetQubit)
	Apply the controlled pauliY (single control, single target) gate, also known as the c-Y and c-sigma-Y gate. More...

void	controlledPhaseFlip (Qureg qureg, int idQubit1, int idQubit2)
	Apply the (two-qubit) controlled phase flip gate, also known as the controlled pauliZ gate. More...

void	controlledPhaseShift (Qureg qureg, int idQubit1, int idQubit2, qreal angle)
	Introduce a phase factor $\exp(i \theta)$ on state $\|11\rangle$ of qubits `idQubit1` and `idQubit2`. More...

void	controlledRotateAroundAxis (Qureg qureg, int controlQubit, int targetQubit, qreal angle, Vector axis)
	Applies a controlled rotation by a given angle around a given vector on the Bloch-sphere. More...

void	controlledRotateX (Qureg qureg, int controlQubit, int targetQubit, qreal angle)
	Applies a controlled rotation by a given angle around the X-axis of the Bloch-sphere. More...

void	controlledRotateY (Qureg qureg, int controlQubit, int targetQubit, qreal angle)
	Applies a controlled rotation by a given angle around the Y-axis of the Bloch-sphere. More...

void	controlledRotateZ (Qureg qureg, int controlQubit, int targetQubit, qreal angle)
	Applies a controlled rotation by a given angle around the Z-axis of the Bloch-sphere. More...

void	controlledTwoQubitUnitary (Qureg qureg, int controlQubit, int targetQubit1, int targetQubit2, ComplexMatrix4 u)
	Apply a general controlled two-qubit unitary (including a global phase factor). More...

void	controlledUnitary (Qureg qureg, int controlQubit, int targetQubit, ComplexMatrix2 u)
	Apply a general controlled unitary (single control, single target), which can include a global phase factor. More...

void	copyStateFromGPU (Qureg qureg)
	In GPU mode, this copies the state-vector (or density matrix) from GPU memory (qureg.deviceStateVec) to RAM (qureg.stateVec), where it can be accessed/modified by the user. More...

void	copyStateToGPU (Qureg qureg)
	In GPU mode, this copies the state-vector (or density matrix) from RAM (qureg.stateVec) to VRAM / GPU-memory (qureg.deviceStateVec), which is the version operated upon by other calls to the API. More...

Qureg	createCloneQureg (Qureg qureg, QuESTEnv env)
	Create a new Qureg which is an exact clone of the passed qureg, which can be either a statevector or a density matrix. More...

ComplexMatrixN	createComplexMatrixN (int numQubits)
	Create (dynamically) a square complex matrix which can be passed to the multi-qubit general unitary functions. More...

Qureg	createDensityQureg (int numQubits, QuESTEnv env)
	Create a Qureg for qubits which are represented by a density matrix, and can be in mixed states. More...

DiagonalOp	createDiagonalOp (int numQubits, QuESTEnv env)
	Creates a DiagonalOp representing a diagonal operator on the full Hilbert space of a Qureg. More...

PauliHamil	createPauliHamil (int numQubits, int numSumTerms)
	Create a `PauliHamil` instance, which is a Hamiltonian expressed as a real-weighted sum of products of Pauli operators. More...

PauliHamil	createPauliHamilFromFile (char *fn)
	Create a `PauliHamil` instance, a real-weighted sum of products of Pauli operators, populated with the data in filename `fn`. More...

QuESTEnv	createQuESTEnv (void)
	Create the QuEST execution environment. More...

Qureg	createQureg (int numQubits, QuESTEnv env)
	Create a Qureg object representing a set of qubits which will remain in a pure state. More...

void	destroyComplexMatrixN (ComplexMatrixN matr)
	Destroy a ComplexMatrixN instance created with createComplexMatrixN() More...

void	destroyDiagonalOp (DiagonalOp op, QuESTEnv env)
	Destroys a DiagonalOp created with createDiagonalOp(), freeing its memory. More...

void	destroyPauliHamil (PauliHamil hamil)
	Destroy a `PauliHamil` instance, created with either createPauliHamil() or createPauliHamilFromFile(). More...

void	destroyQuESTEnv (QuESTEnv env)
	Destroy the QuEST environment. More...

void	destroyQureg (Qureg qureg, QuESTEnv env)
	Deallocate a Qureg object representing a set of qubits. More...

Complex	getAmp (Qureg qureg, long long int index)
	Get the complex amplitude at a given index in the state vector. More...

Complex	getDensityAmp (Qureg qureg, long long int row, long long int col)
	Get an amplitude from a density matrix at a given row and column. More...

void	getEnvironmentString (QuESTEnv env, Qureg qureg, char str[200])
	Sets `str` to a string containing the number of qubits in `qureg`, and the hardware facilities used (e.g. More...

qreal	getImagAmp (Qureg qureg, long long int index)
	Get the imaginary component of the complex probability amplitude at an index in the state vector. More...

long long int	getNumAmps (Qureg qureg)
	Get the number of probability amplitudes in a qureg object, given by 2^numQubits. More...

int	getNumQubits (Qureg qureg)
	Get the number of qubits in a qureg object. More...

qreal	getProbAmp (Qureg qureg, long long int index)
	Get the probability of a state-vector at an index in the full state vector. More...

qreal	getRealAmp (Qureg qureg, long long int index)
	Get the real component of the complex probability amplitude at an index in the state vector. More...

void	hadamard (Qureg qureg, int targetQubit)
	Apply the single-qubit Hadamard gate. More...

void	initBlankState (Qureg qureg)
	Initialises a qureg to have all-zero-amplitudes. More...

void	initClassicalState (Qureg qureg, long long int stateInd)
	Initialise a set of qubits to the classical state (also known as a "computational basis state") with index `stateInd`. More...

void	initComplexMatrixN (ComplexMatrixN m, qreal real[][1<< m.numQubits], qreal imag[][1<< m.numQubits])
	Initialises a ComplexMatrixN instance to have the passed `real` and `imag` values. More...

void	initDebugState (Qureg qureg)
	Initialises `qureg` to be in the un-normalised, non-physical state with with n-th complex amplitude (2n/10 + i(2n+1)/10). More...

void	initDiagonalOp (DiagonalOp op, qreal real, qreal imag)
	Updates the entire DiagonalOp `op` with the given elements, of which there must be 2^`op.numQubits`. More...

void	initPauliHamil (PauliHamil hamil, qreal coeffs, enum pauliOpType codes)
	Initialise a `PauliHamil` instance with the given term coefficients and Pauli codes (one for every qubit in every term). More...

void	initPlusState (Qureg qureg)
	Initialise a set of qubits to the plus state ${\| + \rangle}^{\otimes N} = \frac{1}{\sqrt{2^N}} (\| 0 \rangle + \| 1 \rangle)^{\otimes N}$ (and similarly $\|+\rangle \langle+\|$ for density matrices). More...

void	initPureState (Qureg qureg, Qureg pure)
	Initialise a set of qubits, which can be a state vector or density matrix, to a given pure state. More...

void	initStateFromAmps (Qureg qureg, qreal reals, qreal imags)
	Initialise qureg by specifying the complete statevector. More...

void	initZeroState (Qureg qureg)
	Initialise a set of qubits to the classical zero state ${\| 0 \rangle}^{\otimes N}$ . More...

void	invalidQuESTInputError (const char errMsg, const char errFunc)
	An internal function called when invalid arguments are passed to a QuEST API call, which the user can optionally override by redefining. More...

int	measure (Qureg qureg, int measureQubit)
	Measures a single qubit, collapsing it randomly to 0 or 1. More...

int	measureWithStats (Qureg qureg, int measureQubit, qreal *outcomeProb)
	Measures a single qubit, collapsing it randomly to 0 or 1, and additionally gives the probability of that outcome. More...

void	mixDamping (Qureg qureg, int targetQubit, qreal prob)
	Mixes a density matrix `qureg` to induce single-qubit amplitude damping (decay to 0 state). More...

void	mixDensityMatrix (Qureg combineQureg, qreal prob, Qureg otherQureg)
	Modifies combineQureg to become (1-prob)combineProb + prob otherQureg. More...

void	mixDephasing (Qureg qureg, int targetQubit, qreal prob)
	Mixes a density matrix `qureg` to induce single-qubit dephasing noise. More...

void	mixDepolarising (Qureg qureg, int targetQubit, qreal prob)
	Mixes a density matrix `qureg` to induce single-qubit homogeneous depolarising noise. More...

void	mixKrausMap (Qureg qureg, int target, ComplexMatrix2 *ops, int numOps)
	Apply a general single-qubit Kraus map to a density matrix, as specified by at most four Kraus operators, (`ops`). More...

void	mixMultiQubitKrausMap (Qureg qureg, int targets, int numTargets, ComplexMatrixN ops, int numOps)
	Apply a general N-qubit Kraus map to a density matrix, as specified by at most (2N)^2 Kraus operators. More...

void	mixPauli (Qureg qureg, int targetQubit, qreal probX, qreal probY, qreal probZ)
	Mixes a density matrix `qureg` to induce general single-qubit Pauli noise. More...

void	mixTwoQubitDephasing (Qureg qureg, int qubit1, int qubit2, qreal prob)
	Mixes a density matrix `qureg` to induce two-qubit dephasing noise. More...

void	mixTwoQubitDepolarising (Qureg qureg, int qubit1, int qubit2, qreal prob)
	Mixes a density matrix `qureg` to induce two-qubit homogeneous depolarising noise. More...

void	mixTwoQubitKrausMap (Qureg qureg, int target1, int target2, ComplexMatrix4 *ops, int numOps)
	Apply a general two-qubit Kraus map to a density matrix, as specified by at most sixteen Kraus operators. More...

void	multiControlledMultiQubitUnitary (Qureg qureg, int ctrls, int numCtrls, int targs, int numTargs, ComplexMatrixN u)
	Apply a general multi-controlled multi-qubit unitary (including a global phase factor). More...

void	multiControlledPhaseFlip (Qureg qureg, int *controlQubits, int numControlQubits)
	Apply the multiple-qubit controlled phase flip gate, also known as the multiple-qubit controlled pauliZ gate. More...

void	multiControlledPhaseShift (Qureg qureg, int *controlQubits, int numControlQubits, qreal angle)
	Introduce a phase factor $\exp(i \theta)$ on state $\|1 \dots 1 \rangle$ of the passed qubits. More...

void	multiControlledTwoQubitUnitary (Qureg qureg, int *controlQubits, int numControlQubits, int targetQubit1, int targetQubit2, ComplexMatrix4 u)
	Apply a general multi-controlled two-qubit unitary (including a global phase factor). More...

void	multiControlledUnitary (Qureg qureg, int *controlQubits, int numControlQubits, int targetQubit, ComplexMatrix2 u)
	Apply a general multiple-control single-target unitary, which can include a global phase factor. More...

void	multiQubitUnitary (Qureg qureg, int *targs, int numTargs, ComplexMatrixN u)
	Apply a general multi-qubit unitary (including a global phase factor) with any number of target qubits. More...

void	multiRotatePauli (Qureg qureg, int targetQubits, enum pauliOpType targetPaulis, int numTargets, qreal angle)
	Apply a multi-qubit multi-Pauli rotation on a selected number of qubits. More...

void	multiRotateZ (Qureg qureg, int *qubits, int numQubits, qreal angle)
	Apply a multi-qubit Z rotation on a selected number of qubits. More...

void	multiStateControlledUnitary (Qureg qureg, int controlQubits, int controlState, int numControlQubits, int targetQubit, ComplexMatrix2 u)
	Apply a general multiple-control, conditioned on a specific bit sequence, single-target unitary, which can include a global phase factor. More...

void	pauliX (Qureg qureg, int targetQubit)
	Apply the single-qubit Pauli-X (also known as the X, sigma-X, NOT or bit-flip) gate. More...

void	pauliY (Qureg qureg, int targetQubit)
	Apply the single-qubit Pauli-Y (also known as the Y or sigma-Y) gate. More...

void	pauliZ (Qureg qureg, int targetQubit)
	Apply the single-qubit Pauli-Z (also known as the Z, sigma-Z or phase-flip) gate. More...

void	phaseShift (Qureg qureg, int targetQubit, qreal angle)
	Shift the phase between $\|0\rangle$ and $\|1\rangle$ of a single qubit by a given angle. More...

void	printRecordedQASM (Qureg qureg)
	Print recorded QASM to stdout. More...

void	reportPauliHamil (PauliHamil hamil)
	Print the `PauliHamil` to screen. More...

void	reportQuESTEnv (QuESTEnv env)
	Report information about the QuEST environment. More...

void	reportQuregParams (Qureg qureg)
	Report metainformation about a set of qubits: number of qubits, number of probability amplitudes. More...

void	reportState (Qureg qureg)
	Print the current state vector of probability amplitudes for a set of qubits to file. More...

void	reportStateToScreen (Qureg qureg, QuESTEnv env, int reportRank)
	Print the current state vector of probability amplitudes for a set of qubits to standard out. More...

void	rotateAroundAxis (Qureg qureg, int rotQubit, qreal angle, Vector axis)
	Rotate a single qubit by a given angle around a given Vector on the Bloch-sphere. More...

void	rotateX (Qureg qureg, int rotQubit, qreal angle)
	Rotate a single qubit by a given angle around the X-axis of the Bloch-sphere. More...

void	rotateY (Qureg qureg, int rotQubit, qreal angle)
	Rotate a single qubit by a given angle around the Y-axis of the Bloch-sphere. More...

void	rotateZ (Qureg qureg, int rotQubit, qreal angle)
	Rotate a single qubit by a given angle around the Z-axis of the Bloch-sphere (also known as a phase shift gate). More...

void	seedQuEST (unsigned long int *seedArray, int numSeeds)
	Seed the Mersenne Twister used for random number generation in the QuEST environment with a user defined seed. More...

void	seedQuESTDefault (void)
	Seed the Mersenne Twister used for random number generation in the QuEST environment with an example defualt seed. More...

void	setAmps (Qureg qureg, long long int startInd, qreal reals, qreal imags, long long int numAmps)
	Overwrites a subset of the amplitudes in `qureg`, with those passed in `reals` and `imags`. More...

void	setDiagonalOpElems (DiagonalOp op, long long int startInd, qreal real, qreal imag, long long int numElems)
	Modifies a subset (starting at index `startInd`) of the elements in DiagonalOp `op` with the given elements, of which there are `numElems`. More...

void	setWeightedQureg (Complex fac1, Qureg qureg1, Complex fac2, Qureg qureg2, Complex facOut, Qureg out)
	Modifies qureg `out` to the result of (`facOut` `out` + `fac1` `qureg1` + `fac2` `qureg2`), imposing no constraints on normalisation. More...

void	sGate (Qureg qureg, int targetQubit)
	Apply the single-qubit S gate. More...

void	sqrtSwapGate (Qureg qureg, int qb1, int qb2)
	Performs a sqrt SWAP gate between `qubit1` and `qubit2`. More...

void	startRecordingQASM (Qureg qureg)
	Enable QASM recording. More...

void	stopRecordingQASM (Qureg qureg)
	Disable QASM recording. More...

void	swapGate (Qureg qureg, int qubit1, int qubit2)
	Performs a SWAP gate between `qubit1` and `qubit2`. More...

void	syncDiagonalOp (DiagonalOp op)
	Copy the elements in DiagonalOp `op.real` and `op.imag` to the persisent GPU memory. More...

void	syncQuESTEnv (QuESTEnv env)
	Guarantees that all code up to the given point has been executed on all nodes (if running in distributed mode) More...

int	syncQuESTSuccess (int successCode)
	Performs a logical AND on all successCodes held by all processes. More...

void	tGate (Qureg qureg, int targetQubit)
	Apply the single-qubit T gate. More...

void	twoQubitUnitary (Qureg qureg, int targetQubit1, int targetQubit2, ComplexMatrix4 u)
	Apply a general two-qubit unitary (including a global phase factor). More...

void	unitary (Qureg qureg, int targetQubit, ComplexMatrix2 u)
	Apply a general single-qubit unitary (including a global phase factor). More...

void	writeRecordedQASMToFile (Qureg qureg, char *filename)
	Writes recorded QASM to a file, throwing an error if inaccessible. More...

Detailed Description

The QuEST API. This file contains the comments used by doxygen for generating API doc.

Definition in file QuEST.h.

Data Structures

Macros

Enumerations

Functions

Detailed Description