From 790cedf40e53bd1b861b368c4333ddd4f3045d1b Mon Sep 17 00:00:00 2001
From: Adrian Mak <damarkian@gmail.com>
Date: Tue, 3 Oct 2023 14:40:18 +0800
Subject: [PATCH] update getting-started docs

---
 doc/source/getting-started/ansatz.rst       | 24 +++++++++++++++++++--
 doc/source/getting-started/index.rst        |  2 ++
 doc/source/getting-started/installation.rst |  1 +
 doc/source/getting-started/measurement.rst  |  2 ++
 doc/source/getting-started/molecule.rst     |  1 +
 5 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/doc/source/getting-started/ansatz.rst b/doc/source/getting-started/ansatz.rst
index 6310e0b..db256c8 100644
--- a/doc/source/getting-started/ansatz.rst
+++ b/doc/source/getting-started/ansatz.rst
@@ -7,14 +7,34 @@ A quantum circuit consisting of parameterized gates RX(theta), RY(theta) and RZ(
 Hardware Efficient Ansatz
 -------------------------
 
-Qibochem provides a hardware efficient ansatz that simply consists of a layer of single qubit rotation gates followed by a layer of two-qubit gates that entangle the qubits. For the H\ :sub:`2` case discussed in previous sections, a possible hardware efficient ansatz can be constructed as such:
+Qibochem provides a hardware efficient ansatz that simply consists of a layer of single-qubit rotation gates followed by a layer of two-qubit gates that entangle the qubits. For the H\ :sub:`2` case discussed in previous sections, a possible hardware efficient ansatz can be constructed as such:
 
 .. image:: qibochem_doc_ansatz_hardware-efficient.svg
 
 Example
 ^^^^^^^
 
-Placeholder for hardware-efficient ansatz example
+.. code-block:: python
+
+    from qibochem.ansatz import hardware_efficient
+    import qibo
+
+    nlayers = 1
+    nqubits = 4
+    nfermions = 2
+
+    circuit = qibo.models.Circuit(4)
+    circuit.add(gates.X(_i) for _i in range(nfermions))
+    hardware_efficient_ansatz = hardware_efficient.hea(nlayers, nqubits)
+    circuit.add(hardware_efficient_ansatz)
+    print(circuit.draw())
+
+.. code-block:: output
+
+    q0: ─X──RY─RZ─o─────Z─
+    q1: ─X──RY─RZ─Z─o───|─
+    q2: ─RY─RZ──────Z─o─|─
+    q3: ─RY─RZ────────Z─o─
 
 
 Unitary Coupled Cluster Ansatz
diff --git a/doc/source/getting-started/index.rst b/doc/source/getting-started/index.rst
index b9d719b..13dfb4b 100644
--- a/doc/source/getting-started/index.rst
+++ b/doc/source/getting-started/index.rst
@@ -1,3 +1,4 @@
+===============
 Getting started
 ===============
 
@@ -11,4 +12,5 @@ This section covers the basics of qibochem. More details are given in the follow
     molecule
     hamiltonian
     ansatz
+..
     measurement
diff --git a/doc/source/getting-started/installation.rst b/doc/source/getting-started/installation.rst
index 50bb6f2..6ecf9fb 100644
--- a/doc/source/getting-started/installation.rst
+++ b/doc/source/getting-started/installation.rst
@@ -1,3 +1,4 @@
+============
 Installation
 ============
 
diff --git a/doc/source/getting-started/measurement.rst b/doc/source/getting-started/measurement.rst
index 7123879..d04f1ed 100644
--- a/doc/source/getting-started/measurement.rst
+++ b/doc/source/getting-started/measurement.rst
@@ -1,2 +1,4 @@
+===========
 Measurement
 ===========
+
diff --git a/doc/source/getting-started/molecule.rst b/doc/source/getting-started/molecule.rst
index 520fe6b..92ca7cc 100644
--- a/doc/source/getting-started/molecule.rst
+++ b/doc/source/getting-started/molecule.rst
@@ -1,3 +1,4 @@
+========
 Molecule
 ========