Commit 566223f5 authored by Nguyen, Thien Minh's avatar Nguyen, Thien Minh
Browse files

Added Qcor helper kernels to implement iterative QPE algorithm 



Also, change the code rewrite to use a more distinct variable name of `__ker__temp__` rather than `k` to prevent collision with user params.

Signed-off-by: default avatarThien Nguyen <nguyentm@ornl.gov>
parent 818bf7e9

examples/qpe/qpe_ham_op.cpp

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#include <qcor_qpe>





/// Compile with:

/// qcor -qpu qpp qpe_ham_op.cpp



int main(int argc, char **argv) {

  auto q = qalloc(3);

  auto H = X(0) * X(1);

  int k = 1;

  double omega = 1.234;

  const int num_time_slices = 2;

  std::cout << "Kernel:\n";

  pauli_qpe_iter::print_kernel(std::cout, q, k, omega, H, num_time_slices, true);

}

handlers/qcor_syntax_handler.cpp

+2 −2
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@@ -265,7 +265,7 @@ void QCORSyntaxHandler::GetReplacement( 
    OS << ", " << program_arg_types[i] << " " << program_parameters[i];

  }

  OS << ") {\n";

  OS << "class " << kernel_name << " k(parent, " << program_parameters[0];

  OS << "class " << kernel_name << " __ker__temp__(parent, " << program_parameters[0];

  for (int i = 1; i < program_parameters.size(); i++) {

    OS << ", " << program_parameters[i];

  }
@@ -279,7 +279,7 @@ void QCORSyntaxHandler::GetReplacement( 
    OS << ", " << program_arg_types[i] << " " << program_parameters[i];

  }

  OS << ") {\n";

  OS << "class " << kernel_name << " k(" << program_parameters[0];

  OS << "class " << kernel_name << " __ker__temp__(" << program_parameters[0];

  for (int i = 1; i < program_parameters.size(); i++) {

    OS << ", " << program_parameters[i];

  }

lib/impl/quantum_phase_estimation.hpp

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#pragma once



// Common QCOR kernels to support iterative Quantum Phase Estimation algorithm.



// First-order Trotter evolution

__qpu__ void pauli_trotter_evolution(qreg q, qcor::PauliOperator pauli_ham,

                                     double evo_time, int num_time_slices) {

  const double theta = evo_time / num_time_slices;

  for (int i = 0; i < num_time_slices; ++i) {

    exp_i_theta(q, theta, pauli_ham);

  }

}



// Raise Pauli evolution to a power: i.e. U^power.

__qpu__ void pauli_power_trotter_evolution(qreg q,

                                           qcor::PauliOperator pauli_ham,

                                           double evo_time, int num_time_slices,

                                           int power) {

  for (int i = 0; i < power; ++i) {

    pauli_trotter_evolution(q, pauli_ham, evo_time, num_time_slices);

  }

}



// Kernel for a single iteration of iterative QPE

/// k: the iteration idx.

/// omega: the feedback angle.

/// pauli_ham: hamiltonian

/// num_time_slices: number of trotter steps

/// measure: if true, add measure gate on ancilla qubit.

__qpu__ void pauli_qpe_iter(qreg q, int k, double omega,

                            qcor::PauliOperator pauli_ham, int num_time_slices,

                            int measure) {

  // Ancilla qubit is the last qubit in the register

  auto anc_idx = q.size() - 1;

  // Hadamard on ancilla qubit

  H(q[anc_idx]);

  // Controlled-U

  int power = 1 << (k - 1);

  double evo_time = -2 * M_PI;

  pauli_power_trotter_evolution::ctrl(anc_idx, q, pauli_ham, evo_time,

                                      num_time_slices, power);



  // Rz on ancilla qubit

  Rz(q[anc_idx], omega);

  // Hadamard on ancilla qubit

  H(q[anc_idx]);

  if (measure) {

    Measure(q[anc_idx]);

  }

}
 
 No newline at end of file

lib/qcor_qpe

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#pragma once

#include "impl/quantum_phase_estimation.hpp"

lib/qsim/impls/qsim_impl.cpp

+13 −5
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@@ -121,15 +121,23 @@ VqeWorkflow::execute(const QuatumSimulationModel &model) { 
}



bool IterativeQpeWorkflow::initialize(const HeterogeneousMap &params) {

  // TODO:

  std::cout << "Howdy: initialize\n";

  return true;

  // Default params:

  num_steps = 1;

  num_iters = 1;

  if (params.keyExists<int>("time-steps")) {

    num_steps = params.get<int>("time-steps");

  }



  if (params.keyExists<int>("iterations")) {

    num_iters = params.get<int>("iterations");

  }



  return (num_steps >= 1) && (num_iters >= 1);

}



QuatumSimulationResult

IterativeQpeWorkflow::execute(const QuatumSimulationModel &model) {

  // TODO:

  std::cout << "Howdy: execute\n";

  // 



  return {};

}