[braket] Remove the hardcoded device list and qubit count (#2562)

* Manually tested following files:
  - test_braket.py
  - test_quera.py
  - braket.py with IQM/Garnet and IonQ/Forte-1

Signed-off-by: Pradnya Khalate <[email protected]>

* Update runtime/cudaq/platform/default/rest/helpers/braket/BraketServerHelper.cpp

Co-authored-by: Ryan Shaffer <[email protected]>
Signed-off-by: Pradnya Khalate <[email protected]>

---------

Signed-off-by: Pradnya Khalate <[email protected]>
Signed-off-by: Pradnya Khalate <[email protected]>
Co-authored-by: Ryan Shaffer <[email protected]>

Author: khalatepradnya

python/tests/backends/test_braket.py

@@ -20,8 +20,7 @@
 
 @pytest.fixture(scope="session", autouse=True)
 def do_something():
-    device_arn = "arn:aws:braket:::device/quantum-simulator/amazon/sv1"
-    cudaq.set_target("braket", machine=device_arn)
+    cudaq.set_target("braket")
     yield "Running the tests."
     cudaq.__clearKernelRegistries()
     cudaq.reset_target()

runtime/common/BraketServerHelper.h

@@ -19,40 +19,6 @@
 
 namespace cudaq {
 
-const std::string SV1 = "sv1";
-const std::string DM1 = "dm1";
-const std::string TN1 = "tn1";
-const std::string ARIA1 = "aria1";
-const std::string ARIA2 = "aria2";
-const std::string GARNET = "garnet";
-const std::string AQUILA = "aquila";
-
-const std::string SV1_ARN =
-    "arn:aws:braket:::device/quantum-simulator/amazon/sv1";
-const std::string DM1_ARN =
-    "arn:aws:braket:::device/quantum-simulator/amazon/dm1";
-const std::string TN1_ARN =
-    "arn:aws:braket:::device/quantum-simulator/amazon/tn1";
-const std::string ARIA1_ARN =
-    "arn:aws:braket:us-east-1::device/qpu/ionq/Aria-1";
-const std::string ARIA2_ARN =
-    "arn:aws:braket:us-east-1::device/qpu/ionq/Aria-2";
-const std::string GARNET_ARN =
-    "arn:aws:braket:eu-north-1::device/qpu/iqm/Garnet";
-const std::string AQUILA_ARN =
-    "arn:aws:braket:us-east-1::device/qpu/quera/Aquila";
-
-const std::map<std::string, std::string> deviceArns = {
-    {SV1, SV1_ARN},      {DM1, DM1_ARN},     {TN1, TN1_ARN},
-    {ARIA1, ARIA1_ARN},  {ARIA2, ARIA2_ARN}, {GARNET, GARNET_ARN},
-    {AQUILA, AQUILA_ARN}};
-
-const std::map<std::string, uint> deviceQubitCounts = {
-    {SV1_ARN, 34},   {DM1_ARN, 17},    {TN1_ARN, 50},    {ARIA1_ARN, 25},
-    {ARIA2_ARN, 25}, {GARNET_ARN, 20}, {AQUILA_ARN, 256}};
-
-const uint DEFAULT_QUBIT_COUNT = 50;
-
 /// @brief The BraketServerHelper class extends the ServerHelper class to handle
 /// interactions with the Amazon Braket server for submitting and retrieving
 /// quantum computation jobs.

runtime/cudaq/platform/default/rest/helpers/braket/BraketServerHelper.cpp

@@ -21,22 +21,12 @@ std::string prepareOpenQasm(std::string source) {
 
 namespace cudaq {
 
-std::string getDeviceArn(const std::string &machine) {
-  if (machine.starts_with("arn:aws:braket")) {
+std::string checkDeviceArn(const std::string &machine) {
+  if (machine.starts_with("arn:aws:braket"))
     return machine;
-  }
-
-  if (deviceArns.contains(machine)) {
-    return deviceArns.at(machine);
-  }
-
-  std::string knownMachines;
-  for (const auto &machine : deviceArns)
-    knownMachines += machine.first + " ";
-  const auto errorMessage =
-      fmt::format("Machine \"{}\" is invalid. Machine must be either an Amazon "
-                  "Braket device ARN or one of the known devices: {}",
-                  machine, knownMachines);
+  const auto errorMessage = fmt::format("Machine \"{}\" is invalid. Machine "
+                                        "must be an Amazon Braket device ARN.",
+                                        machine);
   throw std::runtime_error(errorMessage);
 }
 
@@ -51,31 +41,25 @@ BraketServerHelper::getValueOrDefault(const BackendConfig &config,
 // Initialize the Braket server helper with a given backend configuration
 void BraketServerHelper::initialize(BackendConfig config) {
   cudaq::info("Initializing Amazon Braket backend.");
-
   // Fetch machine info before checking emulate because we want to be able to
-  // emulate specific machines.
-  auto machine = getValueOrDefault(config, "machine", SV1);
-  auto deviceArn = getDeviceArn(machine);
+  // emulate specific machines, defaults to state vector simulator
+  auto machine =
+      getValueOrDefault(config, "machine",
+                        "arn:aws:braket:::device/quantum-simulator/amazon/sv1");
+  auto deviceArn = checkDeviceArn(machine);
   cudaq::info("Running on device {}", deviceArn);
-
   config["defaultBucket"] = getValueOrDefault(config, "default_bucket", "");
   config["deviceArn"] = deviceArn;
-  config["qubits"] = deviceQubitCounts.contains(deviceArn)
-                         ? deviceQubitCounts.at(deviceArn)
-                         : DEFAULT_QUBIT_COUNT;
   if (!config["shots"].empty())
     this->setShots(std::stoul(config["shots"]));
-
   const auto emulate_it = config.find("emulate");
   if (emulate_it != config.end() && emulate_it->second == "true") {
     cudaq::info("Emulation is enabled, ignore all Amazon Braket connection "
                 "specific information.");
     backendConfig = std::move(config);
     return;
   }
-
   parseConfigForCommonParams(config);
-
   // Move the passed config into the member variable backendConfig
   backendConfig = std::move(config);
 };
@@ -90,25 +74,19 @@ BraketServerHelper::createJob(std::vector<KernelExecution> &circuitCodes) {
     ServerMessage taskRequest;
     taskRequest["name"] = circuitCode.name;
     taskRequest["deviceArn"] = backendConfig.at("deviceArn");
-
-    taskRequest["qubits"] = backendConfig.at("qubits");
     taskRequest["input"]["format"] = "qasm2";
     taskRequest["input"]["data"] = circuitCode.code;
-
     auto action = nlohmann::json::parse(
         "{\"braketSchemaHeader\": {\"name\": \"braket.ir.openqasm.program\", "
         "\"version\": \"1\"}, \"source\": \"\", \"inputs\": {}}");
     action["source"] = prepareOpenQasm(circuitCode.code);
     taskRequest["action"] = action.dump();
     taskRequest["shots"] = shots;
-
     tasks.push_back(taskRequest);
   }
-
   cudaq::info("Created job payload for braket, language is OpenQASM 2.0, "
               "targeting device {}",
               backendConfig.at("deviceArn"));
-
   return ret;
 };
 

runtime/cudaq/platform/quera/QuEraServerHelper.cpp

@@ -13,23 +13,14 @@ namespace cudaq {
 
 void QuEraServerHelper::initialize(BackendConfig config) {
   cudaq::info("Initializing QuEra via Amazon Braket.");
-
   // Hard-coded for now
-  auto machine = AQUILA;
-  auto deviceArn = AQUILA_ARN;
-
+  auto deviceArn = "arn:aws:braket:us-east-1::device/qpu/quera/Aquila";
   cudaq::info("Running on device {}", deviceArn);
-
   config["defaultBucket"] = getValueOrDefault(config, "default_bucket", "");
   config["deviceArn"] = deviceArn;
-  config["qubits"] = deviceQubitCounts.contains(deviceArn)
-                         ? deviceQubitCounts.at(deviceArn)
-                         : DEFAULT_QUBIT_COUNT;
   if (!config["shots"].empty())
     this->setShots(std::stoul(config["shots"]));
-
   parseConfigForCommonParams(config);
-
   // Move the passed config into the member variable backendConfig
   backendConfig = std::move(config);
 }