RZZ gate for XASM and XACC IR

Signed-off-by: Quantum Brilliance [Simon Yin, Senior Software Engineer] <simon.y@quantum-brilliance.com>

quantum/gate/GateQuantumActivator.cpp

@@ -69,7 +69,10 @@ public:
     auto ifstmt = std::make_shared<xacc::quantum::IfStmt>();
     auto reset = std::make_shared<xacc::quantum::Reset>();
     auto scheduler = std::make_shared<xacc::quantum::PulseScheduler>();
+    auto rzz= std::make_shared<xacc::quantum::RZZ>();
+
     context.RegisterService<xacc::Scheduler>(scheduler);
+    context.RegisterService<xacc::Instruction>(rzz);
 
     context.RegisterService<xacc::Instruction>(h);
     context.RegisterService<xacc::Instruction>(cn);

quantum/gate/ir/CommonGates.hpp

@@ -536,6 +536,24 @@ public:
   DEFINE_VISITABLE()
 };
 
+class RZZ : public Gate {
+public:
+  RZZ() : Gate("RZZ",std::vector<InstructionParameter>{0.0}) {}
+  RZZ(std::size_t controlQubit, std::size_t targetQubit)
+      : Gate("RZZ", std::vector<std::size_t>{controlQubit, targetQubit},
+             std::vector<InstructionParameter>{0.0}) {} 
+  RZZ(std::vector<std::size_t> qbits)
+      : Gate("RZZ", qbits, std::vector<InstructionParameter>{0.0}) {}
+  RZZ(std::size_t controlQubit, std::size_t targetQubit, double theta)
+      : Gate("RZZ", std::vector<std::size_t>{controlQubit, targetQubit},
+             std::vector<InstructionParameter>{theta}) {}
+ 
+  const int nRequiredBits() const override { return 2; }
+
+  DEFINE_CLONE(RZZ)
+  DEFINE_VISITABLE()
+};
+
 } // namespace quantum
 } // namespace xacc
 #endif

quantum/gate/utils/AllGateVisitor.hpp

@@ -48,8 +48,10 @@ class AllGateVisitor : public BaseInstructionVisitor,
                        public InstructionVisitor<U1>,
                        public InstructionVisitor<IfStmt>,
                        public InstructionVisitor<XY>,
-                       public InstructionVisitor<Reset> {
+                       public InstructionVisitor<Reset>,
+                       public InstructionVisitor<RZZ> {
 public:
+  void visit(RZZ &rzz) override {}
   void visit(Hadamard &h) override {}
   void visit(CNOT &h) override {}
   void visit(Rz &h) override {}

quantum/plugins/xasm/tests/XASMCompilerTester.cpp

@@ -22,6 +22,23 @@
 
 #include "Circuit.hpp"
 
+TEST(XASMCompilerTester, checkRZZ) {
+
+  auto compiler = xacc::getCompiler("xasm");
+  auto IR =
+      compiler->compile(R"(
+__qpu__ void rzz_test(qbit q, double theta) {
+  H(q[0]);
+  RZZ(q[0], q[1], theta);
+  CX(q[0], q[1]);
+}
+)");
+
+  auto kernel = IR->getComposites()[0];
+  std::cout << "HELLO: " << kernel->toString() << "\n";
+  std::cout << kernel->operator()({2.4})->toString() << "\n";
+}
+
 TEST (XASMCompilerTester, checkQcorIssue23) {
 auto compiler = xacc::getCompiler("xasm");
   auto IR = compiler->compile(R"(__qpu__ void rotate(qbit q, double x) {