add probabilistic instrument

python/cppsim_wrapper.cpp

@@ -417,7 +417,8 @@ PYBIND11_MODULE(qulacs, m) {
 
     mgate.def("to_matrix_gate", &gate::to_matrix_gate, pybind11::return_value_policy::take_ownership, "Convert named gate to matrix gate", py::arg("gate"));
     mgate.def("Probabilistic", &gate::Probabilistic, pybind11::return_value_policy::take_ownership, "Create probabilistic gate", py::arg("prob_list"), py::arg("gate_list"));
-    mgate.def("CPTP", &gate::CPTP, pybind11::return_value_policy::take_ownership, "Create completely-positive trace preserving map", py::arg("kraus_list"));
+	mgate.def("ProbabilisticInstrument", &gate::ProbabilisticInstrument, pybind11::return_value_policy::take_ownership, "Create probabilistic instrument gate", py::arg("prob_list"), py::arg("gate_list"), py::arg("register"));
+	mgate.def("CPTP", &gate::CPTP, pybind11::return_value_policy::take_ownership, "Create completely-positive trace preserving map", py::arg("kraus_list"));
 	mgate.def("CP", &gate::CP, pybind11::return_value_policy::take_ownership, "Create completely-positive map", py::arg("kraus_list"), py::arg("state_normalize"), py::arg("probability_normalize"), py::arg("assign_zero_if_not_matched"));
 	mgate.def("Instrument", &gate::Instrument, pybind11::return_value_policy::take_ownership, "Create instruments", py::arg("kraus_list"), py::arg("register"));
     mgate.def("Adaptive", &gate::Adaptive, pybind11::return_value_policy::take_ownership, "Create adaptive gate", py::arg("gate"), py::arg("condition"));

src/cppsim/gate_general.hpp

@@ -105,6 +105,88 @@ class QuantumGate_Probabilistic : public QuantumGateBase {
     }
 };
 
+
+/**
+ * \~japanese-en 選択内容を保存する確率的な操作
+ */
+class QuantumGate_ProbabilisticInstrument : public QuantumGateBase {
+protected:
+	Random random;
+	std::vector<double> _distribution;
+	std::vector<double> _cumulative_distribution;
+	std::vector<QuantumGateBase*> _gate_list;
+	UINT _classical_register_address;
+
+public:
+	/**
+	 * \~japanese-en コンストラクタ
+	 *
+	 * @param distribution ゲートが現れる確率
+	 * @param gate_list ゲートのリスト
+	 * @param classical_register 選択結果を保存するアドレス
+	 */
+	QuantumGate_ProbabilisticInstrument(std::vector<double> distribution, std::vector<QuantumGateBase*> gate_list, UINT classical_register_address) {
+		_distribution = distribution;
+		_classical_register_address = classical_register_address;
+
+		double sum = 0.;
+		_cumulative_distribution.push_back(0.);
+		for (auto val : distribution) {
+			sum += val;
+			_cumulative_distribution.push_back(sum);
+		}
+		for (auto gate : gate_list) {
+			_gate_list.push_back(gate->copy());
+		}
+	};
+
+	virtual ~QuantumGate_ProbabilisticInstrument() {
+		for (unsigned int i = 0; i < _gate_list.size(); ++i) {
+			delete _gate_list[i];
+		}
+	}
+
+	/**
+	 * \~japanese-en 量子状態を更新する
+	 *
+	 * @param state 更新する量子状態
+	 */
+	virtual void update_quantum_state(QuantumStateBase* state) override {
+		double r = random.uniform();
+		auto ite = std::lower_bound(_cumulative_distribution.begin(), _cumulative_distribution.end(), r);
+		assert(ite != _cumulative_distribution.begin());
+		size_t gate_index = std::distance(_cumulative_distribution.begin(), ite) - 1;
+
+		if (gate_index < _gate_list.size()) {
+			_gate_list[gate_index]->update_quantum_state(state);
+		}
+		state->set_classical_value(this->_classical_register_address,gate_index);
+	};
+	/**
+	 * \~japanese-en 自身のディープコピーを生成する
+	 *
+	 * @return 自身のディープコピー
+	 */
+	virtual QuantumGateBase* copy() const override {
+		std::vector<QuantumGateBase*> new_gate_list;
+		for (auto item : _gate_list) {
+			new_gate_list.push_back(item->copy());
+		}
+		return new QuantumGate_ProbabilisticInstrument(_distribution, new_gate_list, _classical_register_address);
+	};
+
+	/**
+	 * \~japanese-en 自身のゲート行列をセットする
+	 *
+	 * @param matrix 行列をセットする変数の参照
+	 */
+	virtual void set_matrix(ComplexMatrix& matrix) const override {
+		std::cerr << "* Warning : Gate-matrix of probabilistic gate cannot be obtained. Identity matrix is returned." << std::endl;
+		matrix = Eigen::MatrixXcd::Ones(1, 1);
+	}
+};
+
+
 /**
  * \~japanese-en Kraus表現のCPTP-map
  */

src/cppsim/gate_merge.cpp

@@ -344,6 +344,10 @@ namespace gate {
         return new QuantumGate_Probabilistic(distribution, gate_list);
     }
 
+	QuantumGateBase* ProbabilisticInstrument(std::vector<double> distribution, std::vector<QuantumGateBase*> gate_list, UINT classical_register_address) {
+		return new QuantumGate_ProbabilisticInstrument(distribution, gate_list, classical_register_address);
+	}
+
     QuantumGateBase* CPTP(std::vector<QuantumGateBase*> gate_list) {
         return new QuantumGate_CPTP(gate_list);
     }

src/cppsim/gate_merge.hpp

@@ -65,6 +65,17 @@ namespace gate {
      */
     DllExport QuantumGateBase* Probabilistic(std::vector<double> distribution, std::vector<QuantumGateBase*> gate_list);
 
+	/**
+	 * \~japanese-en 密度行列にも確率的に作用する量子ゲートを作成する。
+	 *
+	 * 確率分布の総和が1でない場合、残った確率が採用されたときには何も作用しない。
+	 * @param distribution 確率分布
+	 * @param gate_list 作用する量子ゲート
+	 * @param classical_register_address 作用したゲートの添え字を保存するアドレス
+	 * @return 確率的に作用するゲート
+	 */
+	DllExport QuantumGateBase* ProbabilisticInstrument(std::vector<double> distribution, std::vector<QuantumGateBase*> gate_list, UINT classical_register_address);
+
     /**
      * \~japanese-en CPTP-mapを作成する
      *