From b8f0f33f01b7ec1b2bf0b99e547a14ab2a99473e Mon Sep 17 00:00:00 2001
From: Jean-Christophe Jaskula <jjaskula@amazon.com>
Date: Tue, 28 Nov 2023 11:24:15 +0100
Subject: [PATCH] update docstring

---
 src/braket/circuits/gates.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/braket/circuits/gates.py b/src/braket/circuits/gates.py
index a1c881395..29d223c26 100644
--- a/src/braket/circuits/gates.py
+++ b/src/braket/circuits/gates.py
@@ -266,6 +266,12 @@ def gphase(
     ) -> Instruction | Iterable[Instruction]:
         r"""Global phase gate.
 
+        If the gate is applied with control/negative control modifiers, it is translated in an
+        equivalent gate using the following definition: `phaseshift(λ) = ctrl @ gphase(λ)`.
+        The rightmost control qubit is used for the translation. If the polarity of the rightmost
+        control modifier is negative, the following identity is used:
+        `negctrl @ gphase(λ) q = x q; ctrl @ gphase(λ) q; x q`.
+
         Unitary matrix:
 
             .. math:: \mathtt{gphase}(\gamma) = e^(i \gamma) I_1.