Decompose QFT

unitaryfund · May 31, 2024 · 9b67ca5 · 9b67ca5
1 parent 0ea3c80
commit 9b67ca5
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Showing 3 changed files with 1 addition and 24 deletions.
diff --git a/pennylane_qrack/QrackDeviceConfig.toml b/pennylane_qrack/QrackDeviceConfig.toml
@@ -48,7 +48,6 @@ U2 = { properties = [ "controllable", "invertible" ] }
 U1 = { properties = [ "controllable", "invertible" ] }
 MultiControlledX = { properties = [ "controllable", "invertible" ] }
 Identity = { properties = [ "controllable", "invertible" ] }
-QFT = { properties = [ "invertible" ] }
 
 # Operators that should be decomposed according to the algorithm used
 # by PennyLane's device API.
@@ -79,6 +78,7 @@ QFT = { properties = [ "invertible" ] }
 # IsingYY = {}
 # IsingZZ = {}
 # IsingXY = {}
+# QFT = {}
 
 # Gates which should be translated to QubitUnitary
 # [operators.gates.matrix]

diff --git a/pennylane_qrack/qrack_device.cpp b/pennylane_qrack/qrack_device.cpp
@@ -192,20 +192,6 @@ struct QrackDevice final : public Catalyst::Runtime::QuantumDevice {
                     qsim->U(target, Qrack::PI_R1 / 2, params[0U], params[1U]);
                 }
             }
-        } else if (name == "QFT") {
-            const size_t maxLcv = wires.size() >> 1U;
-            const size_t end = wires.size() - 1U;
-            if (inverse) {
-                for (size_t i = 0U; i < maxLcv; ++i) {
-                    qsim->Swap(wires[i], wires[end - i]);
-                }
-                qsim->IQFTR(wires);
-            } else {
-                qsim->QFTR(wires);
-                for (size_t i = 0U; i < maxLcv; ++i) {
-                    qsim->Swap(wires[i], wires[end - i]);
-                }
-            }
         } else if (name != "Identity") {
             throw std::domain_error("Unrecognized gate name: " + name);
         }

diff --git a/pennylane_qrack/qrack_device.py b/pennylane_qrack/qrack_device.py
@@ -154,7 +154,6 @@ class QrackDevice(QubitDevice):
         "C(CPhase)",
         "MultiControlledX",
         "C(MultiControlledX)",
-        "QFT",
     }
 
     config = pathlib.Path(
@@ -598,14 +597,6 @@ def _apply_gate(self, op):
                 -par[1],
                 -par[2],
             )
-        elif opname == "QFT":
-            self._state.qft(device_wires.labels)
-            for i in range(len(device_wires.labels) >> 1):
-                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
-        elif opname == "QFT.inv":
-            for i in range(len(device_wires.labels) >> 1):
-                self._state.swap(device_wires.labels[i], device_wires.labels[-i])
-            self._state.iqft(device_wires.labels)
         elif opname not in [
             "Identity",
             "Identity.inv",