From 1a90225437ad9f61d85fbc3127590caf52b4efc3 Mon Sep 17 00:00:00 2001
From: arvak-quantum <dhinderink@gmail.com>
Date: Sun, 10 May 2026 14:41:41 +0200
Subject: [PATCH 1/2] senate(fix-#991): create
 spec/examples/xxz_spin_chain_12q.cbor.hex via qwen3-coder

---
 spec/examples/xxz_spin_chain_12q.cbor.hex | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 spec/examples/xxz_spin_chain_12q.cbor.hex

diff --git a/spec/examples/xxz_spin_chain_12q.cbor.hex b/spec/examples/xxz_spin_chain_12q.cbor.hex
new file mode 100644
index 0000000..0b936e7
--- /dev/null
+++ b/spec/examples/xxz_spin_chain_12q.cbor.hex
@@ -0,0 +1 @@
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From 31cb68cd76fdbe7b92239a04b4af399b254eb44b Mon Sep 17 00:00:00 2001
From: arvak-quantum <dhinderink@gmail.com>
Date: Sun, 10 May 2026 14:41:41 +0200
Subject: [PATCH 2/2] senate(fix-#991): create
 spec/examples/xxz_spin_chain_12q.md via qwen3-coder

---
 spec/examples/xxz_spin_chain_12q.md | 40 +++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 spec/examples/xxz_spin_chain_12q.md

diff --git a/spec/examples/xxz_spin_chain_12q.md b/spec/examples/xxz_spin_chain_12q.md
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+# XXZ Spin Chain (12 Qubits)
+
+## Physics Description
+
+The XXZ spin chain is a one-dimensional quantum spin model with anisotropic interactions, described by the Hamiltonian:
+
+$$H = J \sum_{i=0}^{N-2} (\sigma_i^x \sigma_{i+1}^x + \sigma_i^y \sigma_{i+1}^y + \Delta \sigma_i^z \sigma_{i+1}^z)$$
+
+Where:
+- $J$ is the coupling strength (set to 1.0)
+- $\Delta$ is the anisotropy parameter (set to 1.0 for the Heisenberg point)
+- $N$ is the number of qubits (12 in this example)
+
+This model exhibits rich physics including quantum phase transitions as the anisotropy parameter $\Delta$ is varied:
+- $\Delta < -1$: Ferromagnetic Ising phase
+- $-1 < \Delta < 1$: XY phase with algebraic decay of correlations
+- $\Delta > 1$: Antiferromagnetic Ising phase
+
+## Parameters
+
+- **Qubits**: 12
+- **Coupling strength (J)**: 1.0 GHz·rad
+- **Anisotropy parameter (Δ)**: 1.0 (Heisenberg point)
+- **Evolution time**: 10.0 μs
+- **Trotter steps**: 1
+- **Required T1**: 100.0 μs
+- **Required T2**: 100.0 μs
+
+## Expected Results
+
+At the Heisenberg point ($\Delta = 1$), this model exhibits SU(2) symmetry and is expected to show antiferromagnetic correlations. The ground state has total spin $S_{total} = 0$ for even $N$, with alternating spin expectation values along the z-axis.
+
+The energy per bond is expected to approach $E_0/N \approx -0.443$ GHz·rad in the thermodynamic limit, with finite-size corrections for the 12-qubit chain.
+
+## Circuit Properties
+
+- **Depth**: ~50 gates
+- **CX gates**: 22 (nearest-neighbor)
+- **Single-qubit gates**: 24 (hadamard and phase)
+- **Qubit connectivity**: Linear chain (0-1-2-...-11)
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