From f7c25704cfbc215a07a4695b916cf4a4057aec0d Mon Sep 17 00:00:00 2001
From: Jun Doi <doichan@jp.ibm.com>
Date: Thu, 30 May 2024 18:14:17 +0900
Subject: [PATCH] Move delay gate to custom instructions (#2153)

---
 qiskit_aer/backends/aer_simulator.py                      | 8 ++++++++
 qiskit_aer/backends/backend_utils.py                      | 8 --------
 .../add_delay_custom_instructions-e1bf80ec3598bfd1.yaml   | 6 ++++++
 3 files changed, 14 insertions(+), 8 deletions(-)
 create mode 100644 releasenotes/notes/add_delay_custom_instructions-e1bf80ec3598bfd1.yaml

diff --git a/qiskit_aer/backends/aer_simulator.py b/qiskit_aer/backends/aer_simulator.py
index fbaae948f0..e1676ce61a 100644
--- a/qiskit_aer/backends/aer_simulator.py
+++ b/qiskit_aer/backends/aer_simulator.py
@@ -525,6 +525,7 @@ class AerSimulator(AerBackend):
                 "continue_loop",
                 "reset",
                 "switch_case",
+                "delay",
             ]
         ),
         "density_matrix": sorted(
@@ -549,6 +550,7 @@ class AerSimulator(AerBackend):
                 "continue_loop",
                 "reset",
                 "switch_case",
+                "delay",
             ]
         ),
         "matrix_product_state": sorted(
@@ -575,6 +577,7 @@ class AerSimulator(AerBackend):
                 "continue_loop",
                 "reset",
                 "switch_case",
+                "delay",
             ]
         ),
         "stabilizer": sorted(
@@ -598,6 +601,7 @@ class AerSimulator(AerBackend):
                 "continue_loop",
                 "reset",
                 "switch_case",
+                "delay",
             ]
         ),
         "extended_stabilizer": sorted(
@@ -607,6 +611,7 @@ class AerSimulator(AerBackend):
                 "roerror",
                 "save_statevector",
                 "reset",
+                "delay",
             ]
         ),
         "unitary": sorted(
@@ -615,6 +620,7 @@ class AerSimulator(AerBackend):
                 "save_unitary",
                 "set_unitary",
                 "reset",
+                "delay",
             ]
         ),
         "superop": sorted(
@@ -627,6 +633,7 @@ class AerSimulator(AerBackend):
                 "save_superop",
                 "set_superop",
                 "reset",
+                "delay",
             ]
         ),
         "tensor_network": sorted(
@@ -650,6 +657,7 @@ class AerSimulator(AerBackend):
                 "set_density_matrix",
                 "reset",
                 "switch_case",
+                "delay",
             ]
         ),
     }
diff --git a/qiskit_aer/backends/backend_utils.py b/qiskit_aer/backends/backend_utils.py
index 66d165d41c..a030578b6c 100644
--- a/qiskit_aer/backends/backend_utils.py
+++ b/qiskit_aer/backends/backend_utils.py
@@ -114,7 +114,6 @@
             "diagonal",
             "multiplexer",
             "initialize",
-            "delay",
             "pauli",
             "mcx_gray",
             "ecr",
@@ -155,7 +154,6 @@
             "ccx",
             "unitary",
             "diagonal",
-            "delay",
             "pauli",
             "ecr",
         ]
@@ -186,7 +184,6 @@
             "ccx",
             "unitary",
             "roerror",
-            "delay",
             "pauli",
             "r",
             "rx",
@@ -218,7 +215,6 @@
             "cy",
             "cz",
             "swap",
-            "delay",
             "pauli",
             "ecr",
             "rz",
@@ -245,7 +241,6 @@
             "p",
             "ccx",
             "ccz",
-            "delay",
             "pauli",
             "ecr",
             "rz",
@@ -311,7 +306,6 @@
             "unitary",
             "diagonal",
             "multiplexer",
-            "delay",
             "pauli",
             "ecr",
         ]
@@ -351,7 +345,6 @@
             "ccx",
             "unitary",
             "diagonal",
-            "delay",
             "pauli",
         ]
     ),
@@ -416,7 +409,6 @@
             "diagonal",
             "multiplexer",
             "initialize",
-            "delay",
             "pauli",
             "mcx_gray",
             "ecr",
diff --git a/releasenotes/notes/add_delay_custom_instructions-e1bf80ec3598bfd1.yaml b/releasenotes/notes/add_delay_custom_instructions-e1bf80ec3598bfd1.yaml
new file mode 100644
index 0000000000..7a146ce77b
--- /dev/null
+++ b/releasenotes/notes/add_delay_custom_instructions-e1bf80ec3598bfd1.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Add/move `delay` gate to default custom instructions for `AerSimulator.configulation`
+    to resolve error reported in issue #2152, `delay` was not in `basis_gates`
+    when AerSimulator is made by `from_backend`