;;;; Example Bell state creation circuits
(in-package :cl-quantum/examples)

(defun make-bell-phi+-circuit ()
  "Return a circuit that makes a Bell phi+ state. That is |00>+|11>."
  (with-build-circuit
    (:h 0)
    (:cnot 1 0)))

(defun make-bell-phi--circuit ()
  "Return a circuit that makes a Bell phi- state. That is |00>-|11>."
  (with-build-circuit
    (:h 0)
    (:cnot 1 0)
    (:z 1)))

(defun make-bell-psi+-circuit ()
  "Return a circuit that makes a Bell psi+ state. That is |01>+|10>."
  (with-build-circuit
    (:x 1)
    (:h 0)
    (:cnot 1 0)))

(defun make-bell-psi--circuit ()
  "Return a circuit that makes a Bell psi- state. That is |01>-|10>."
  (with-build-circuit
    (:x 1)
    (:h 0)
    (:cnot 1 0)
    (:z 1)))