Commit 0f5114d3 authored by Nguyen, Thien Minh's avatar Nguyen, Thien Minh
Browse files

Fixed up QCOR examples for FTQC runtime 



Signed-off-by: default avatarThien Nguyen <nguyentm@ornl.gov>
parent 466463da

examples/ftqc_qrt/repeat-until-success.cpp

+26 −24
Original line number Diff line number Diff line
@@ -5,39 +5,41 @@ 
// If not using the "ftqc" QRT, this will cause errors since the Measure results

// are not available yet.



__qpu__ void rus(qreg q, int maxIter) {

// Using Repeat-Until-Success pattern to prepare a quantum state.

// https://docs.microsoft.com/en-us/quantum/user-guide/using-qsharp/control-flow#rus-to-prepare-a-quantum-state

__qpu__ void PrepareStateUsingRUS(qreg q, int maxIter) {

  using qcor::xasm;

  // Note: control = q[0], eigenstate = q[1]

  // U = Z; P = X

  bool measuredZero = false;

  bool measuredOne = false;

  X(q[1]);

  // Note: target = q[0], aux = q[1]

  H(q[1]);

  // We limit the max number of RUS iterations.

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

    std::cout << "Iter: " << i << "\n";

    H(q[0]);

    CZ(q[0], q[1]);

    H(q[0]);

    Measure(q[0]);

    if (q.cReg(0)) {

      // Fix up: if measure = 1, reset the control qubit back to 0.

      // Note: the eigenstate qubit remains coherent during this RUS loop.

      X(q[0]);

    }

    Tdg(q[1]);

    CNOT(q[0], q[1]);

    T(q[1]);



    measuredZero = measuredZero || (q.cReg(0) == false);

    measuredOne = measuredOne || (q.cReg(0) == true);

    if (measuredZero && measuredOne) {

      std::cout << "Success after " << i << " iterations.\n";

    // In order to measure in the PauliX basis, changes the basis.

    H(q[1]);

    Measure(q[1]);

    bool outcome = q.cReg(1);

    if (!outcome) {

      // Success (until (outcome == Zero))

      std::cout << "Success after " << i + 1 << " iterations.\n";

      break;

    }

    // Fix up: Bring the auxiliary and target qubits back to |+> state.

    if (outcome) {

      // Measure 1: |1> state

      X(q[1]);

      H(q[1]);

      X(q[0]);

      H(q[0]);

    } 



  if (!measuredZero || !measuredOne) {

    std::cout << "Failed!!!\n";

  }

}



int main() {

  // qcor::set_verbose(true);

  auto q = qalloc(2);

  rus(q, 100);

  PrepareStateUsingRUS(q, 100);

}

examples/ftqc_qrt/simple-demo.cpp

+1 −1
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ __qpu__ void bell(qreg q, int nbRuns) { 
    CX(q[0], q[1]);

    Measure(q[0]);

    Measure(q[1]);

    if (q.cReg(0) && q.cReg(1)) {

    if (q.cReg(0) == q.cReg(1)) {

      std::cout << "Iter " << i << ": Matched!\n";

    } else {

      // Should only happen if using a real (noisy) backend.