Merge pull request #277 from kevinsung/sx

Add SX and SXDG gates

Author: jcmgray

quimb/tensor/circuit.py

@@ -6,6 +6,7 @@
 - [ ] multi qubit gates via MPO for MPS simulation
 """
 
+import cmath
 import functools
 import itertools
 import math
@@ -419,6 +420,8 @@ def register_special_gate(name, fn, num_qubits, tag=None, array=None):
 register_constant_gate("SDG", qu.S_gate().H, 1)
 register_constant_gate("T", qu.T_gate(), 1)
 register_constant_gate("TDG", qu.T_gate().H, 1)
+register_constant_gate("SX", cmath.rect(1, 0.25 * math.pi) * qu.Xsqrt(), 1)
+register_constant_gate("SXDG", cmath.rect(1, -0.25 * math.pi) * qu.Xsqrt().H, 1)
 register_constant_gate("X_1_2", qu.Xsqrt(), 1, "X_1/2")
 register_constant_gate("Y_1_2", qu.Ysqrt(), 1, "Y_1/2")
 register_constant_gate("Z_1_2", qu.Zsqrt(), 1, "Z_1/2")
@@ -2038,6 +2041,12 @@ def t(self, i, gate_round=None, **kwargs):
     def tdg(self, i, gate_round=None, **kwargs):
         self.apply_gate("TDG", i, gate_round=gate_round, **kwargs)
 
+    def sx(self, i, gate_round=None, **kwargs):
+        self.apply_gate("SX", i, gate_round=gate_round, **kwargs)
+
+    def sxdg(self, i, gate_round=None, **kwargs):
+        self.apply_gate("SXDG", i, gate_round=gate_round, **kwargs)
+
     def x_1_2(self, i, gate_round=None, **kwargs):
         self.apply_gate("X_1_2", i, gate_round=gate_round, **kwargs)
 

tests/test_tensor/test_circuit.py

@@ -235,8 +235,12 @@ def test_all_gate_methods(self, Circ):
             ("y", 1, 0),
             ("z", 1, 0),
             ("s", 1, 0),
+            ("sdg", 1, 0),
             ("t", 1, 0),
+            ("tdg", 1, 0),
             ("h", 1, 0),
+            ("sx", 1, 0),
+            ("sxdg", 1, 0),
             ("iden", 1, 0),
             ("x_1_2", 1, 0),
             ("y_1_2", 1, 0),