"p">[</span><span class="s2">&quot;spin_polerised&quot;</span><span class="p">]</span>
        <span class="n">v_x</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">zeros</span><span class="p">(</span><span class="n">shape</span><span class="o">=</span><span class="n">s</span><span class="o">.</span><span class="n">x</span><span class="o">.</span><span class="n">shape</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span>
        <span