Merge pull request #90 from tnguyen-ornl/fix-u-gate

Fixes for #89

Author: 1tnguyen

tnqvm/base/Gates.hpp

@@ -221,6 +221,19 @@ namespace tnqvm {
         };    
     }
 
+    template <>
+    std::vector<std::vector<std::complex<double>>>
+    GetGateMatrix<CommonGates::U>(double in_theta, double in_phi,
+                                  double in_lambda) {
+      return {
+          {std::cos(in_theta / 2.0),
+           -std::exp(std::complex<double>(0, in_lambda)) *
+               std::sin(in_theta / 2.0)},
+          {std::exp(std::complex<double>(0, in_phi)) * std::sin(in_theta / 2.0),
+           std::exp(std::complex<double>(0, in_phi + in_lambda)) *
+               std::cos(in_theta / 2.0)}};
+    }
+
     template <> 
     std::vector<std::vector<std::complex<double>>> GetGateMatrix<CommonGates::CNOT>() {
         return 

tnqvm/visitors/exatn-dm/ExaTnDmVisitor.cpp

@@ -143,6 +143,11 @@ getGateMatrix(const xacc::Instruction &in_gate, bool in_dagger = false) {
     case CommonGates::Rz:
       return GetGateMatrix<CommonGates::Rz>(
           in_gate.getParameter(0).as<double>());
+    case CommonGates::U:
+      return GetGateMatrix<CommonGates::U>(
+          in_gate.getParameter(0).as<double>(),
+          in_gate.getParameter(1).as<double>(),
+          in_gate.getParameter(2).as<double>());
     case CommonGates::I:
       return GetGateMatrix<CommonGates::I>();
     case CommonGates::H:

tnqvm/visitors/exatn-mpo/ExaTnPmpsVisitor.cpp

@@ -154,8 +154,15 @@ std::vector<std::complex<double>> getGateMatrix(const xacc::Instruction& in_gate
             case CommonGates::X: return GetGateMatrix<CommonGates::X>();
             case CommonGates::Y: return GetGateMatrix<CommonGates::Y>();
             case CommonGates::Z: return GetGateMatrix<CommonGates::Z>();
-            case CommonGates::T: return GetGateMatrix<CommonGates::T>();
-            case CommonGates::Tdg: return GetGateMatrix<CommonGates::Tdg>();
+            case CommonGates::T:
+              return GetGateMatrix<CommonGates::T>();
+            case CommonGates::U:
+              return GetGateMatrix<CommonGates::U>(
+                  in_gate.getParameter(0).as<double>(),
+                  in_gate.getParameter(1).as<double>(),
+                  in_gate.getParameter(2).as<double>());
+            case CommonGates::Tdg:
+              return GetGateMatrix<CommonGates::Tdg>();
             case CommonGates::CNOT: return GetGateMatrix<CommonGates::CNOT>();
             case CommonGates::Swap: return GetGateMatrix<CommonGates::Swap>();
             case CommonGates::iSwap: return GetGateMatrix<CommonGates::iSwap>();

tnqvm/visitors/exatn-mps/ExatnUtils.cpp

@@ -56,8 +56,15 @@ GateTensor GateTensorConstructor::getGateTensor(xacc::Instruction& in_gate)
             case CommonGates::Y: return GetGateMatrix<CommonGates::Y>();
             case CommonGates::Z: return GetGateMatrix<CommonGates::Z>();
             case CommonGates::T: return GetGateMatrix<CommonGates::T>();
-            case CommonGates::Tdg: return GetGateMatrix<CommonGates::Tdg>();
-            case CommonGates::CNOT: return GetGateMatrix<CommonGates::CNOT>();
+            case CommonGates::Tdg:
+              return GetGateMatrix<CommonGates::Tdg>();
+            case CommonGates::U:
+              return GetGateMatrix<CommonGates::U>(
+                  in_gate.getParameter(0).as<double>(),
+                  in_gate.getParameter(1).as<double>(),
+                  in_gate.getParameter(2).as<double>());
+            case CommonGates::CNOT:
+              return GetGateMatrix<CommonGates::CNOT>();
             case CommonGates::Swap: return GetGateMatrix<CommonGates::Swap>();
             case CommonGates::iSwap: return GetGateMatrix<CommonGates::iSwap>();
             case CommonGates::fSim: return GetGateMatrix<CommonGates::fSim>(in_gate.getParameter(0).as<double>(), in_gate.getParameter(1).as<double>());

tnqvm/visitors/exatn/ExatnVisitor.cpp

@@ -924,7 +924,11 @@ void ExatnVisitor<TNQVM_COMPLEX_TYPE>::visit(CPhase &in_CPhaseGate) {
 template<typename TNQVM_COMPLEX_TYPE>
 void ExatnVisitor<TNQVM_COMPLEX_TYPE>::visit(U &in_UGate) {
   TNQVM_TELEMETRY_ZONE(__FUNCTION__, __FILE__, __LINE__);
-  appendGateTensor<CommonGates::U>(in_UGate);
+  assert(in_UGate.nParameters() == 3);
+  const double theta = in_UGate.getParameter(0).as<double>();
+  const double phi = in_UGate.getParameter(1).as<double>();
+  const double lambda = in_UGate.getParameter(2).as<double>();
+  appendGateTensor<CommonGates::U>(in_UGate, theta, phi, lambda);
 }
 
 template<typename TNQVM_COMPLEX_TYPE>

tnqvm/visitors/itensor/mps/ITensorMPSVisitor.cpp

@@ -490,15 +490,27 @@ void ITensorMPSVisitor::visit(Rz &gate) {
   execTime += singleQubitTime;
 }
 
-void ITensorMPSVisitor::visit(U& u) {
-    Rz z1(u.bits()[0], ipToDouble(u.getParameter(0)));
-    Ry y(u.bits()[0], ipToDouble(u.getParameter(1)));
-    Rz z2(u.bits()[0], ipToDouble(u.getParameter(2)));
-
-    visit(z1);
-    visit(y);
-    visit(z2);
+void ITensorMPSVisitor::visit(U &u) {
+  auto iqbit_in = u.bits()[0];
+  if (verbose) {
+    std::cout << "applying " << u.name() << " @ " << iqbit_in << std::endl;
   }
+  const double theta = ipToDouble(u.getParameter(0));
+  const double phi = ipToDouble(u.getParameter(1));
+  const double lambda = ipToDouble(u.getParameter(2));
+  auto ind_in = ind_for_qbit(iqbit_in);
+  auto ind_out = itensor::Index(u.name(), 2);
+  auto tGate = itensor::ITensor(ind_in, ind_out);
+  tGate.set(ind_in(1), ind_out(1), std::cos(theta / 2.0));
+  tGate.set(ind_in(1), ind_out(2), -std::exp(std::complex<double>(0, lambda)) *
+               std::sin(theta / 2.0));
+  tGate.set(ind_in(2), ind_out(1), std::exp(std::complex<double>(0, phi)) * std::sin(theta / 2.0));
+  tGate.set(ind_in(2), ind_out(2), std::exp(std::complex<double>(0, phi + lambda)) *
+               std::cos(theta / 2.0));
+  legMats[iqbit_in] = tGate * legMats[iqbit_in];
+  printWavefunc();
+  execTime += singleQubitTime;
+}
 
 void ITensorMPSVisitor::visit(CPhase &cp) {
   xacc::error("ITensorMPS Visitor CPhase visit unimplemented.");