California Code, Probate Code - PROB § 9805

(a) The personal representative shall execute and deliver the mortgage or deed of trust, or execute and deliver the instrument creating the security interest, setting forth therein that it is made by authority of the order, giving the date of the order.

(b) The note and the mortgage or deed of trust or other instrument creating the security interest, if any, shall be signed by the personal representative and shall be acknowledged by the personal representative if the instrument creates a lien on real property.