diff --git a/src/qibojit/backends/matrices.py b/src/qibojit/backends/matrices.py
index e538f67..a6622d1 100644
--- a/src/qibojit/backends/matrices.py
+++ b/src/qibojit/backends/matrices.py
@@ -75,6 +75,9 @@ def __init__(self, dtype):
 
         self.cp = cp
 
+    def I(self, n=2):
+        return self.cp.eye(n, dtype=self.dtype)
+
     def _cast(self, x, dtype):
         is_cupy = [
             isinstance(item, self.cp.ndarray) for sublist in x for item in sublist