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<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Quantum Computation Language</span></span>
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<p><b>Quantum Computation Language</b> (<b>QCL</b>) is one of the first implemented <a href="Quantum_programming" title="Quantum programming">quantum programming</a> <a href="Programming_languages" class="mw-redirect" title="Programming languages">languages</a>.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> The most important feature of QCL is the support for user-defined operators and functions. Its <a href="Syntax" title="Syntax">syntax</a> resembles the syntax of the <a href="C_programming_language" class="mw-redirect" title="C programming language">C programming language</a> and its classical <a href="Data_type" title="Data type">data types</a> are similar to primitive data types in C. One can combine classical code and quantum code in the same program.
</p><p>The language was created before there were multi-qubit quantum computers and the only implementation of QCL uses an interpreter with a built-in classically simulated quantum computer.
</p><p>QCL was created to explore programming concepts for quantum computers.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup>
</p><p>The QCL library provides standard quantum operators used in quantum algorithms such as:<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>
</p>
<ul><li>Controlled-not with many target qubits,</li>
<li><a href="Hadamard_operation" class="mw-redirect" title="Hadamard operation">Hadamard operation</a> on many qubits,</li>
<li>Phase and controlled phase.</li>
<li>Quantum algorithms for addition, multiplication and exponentiation with binary constants (all modulus n)</li>
<li>The <a href="Quantum_Fourier_transform" title="Quantum Fourier transform">quantum fourier transform</a></li></ul>
<div class="mw-heading mw-heading2"><h2 id="Syntax">Syntax</h2></div>
<ul><li>Data types
<ul><li>Quantum - qureg, quvoid, quconst, quscratch, qucond</li>
<li>Classical - int, real, complex, boolean, string, vector, matrix, tensor</li></ul></li>
<li>Function types
<ul><li>qufunct - Pseudo-classic operators. Can only change the permutation of basis states.</li>
<li>operator - General unitary operators. Can change the amplitude.</li>
<li>procedure - Can call measure, print, and dump inside this function. This function is non-invertible.</li></ul></li>
<li>Built-in functions
<ul><li>Quantum
<ul><li>qufunct - Fanout, Swap, Perm2, Perm4, Perm8, Not, CNot</li>
<li>operator - Matrix2x2, Matrix4x4, Matrix8x8, Rot, Mix, H, CPhase, SqrtNot, X, Y, Z, S, T</li>
<li>procedure - measure, dump, reset</li></ul></li>
<li>Classical
<ul><li>Arithmetic - sin, cos, tan, log, sqrt, ...</li>
<li>Complex - Re, Im, conj</li></ul></li></ul></li></ul>
<div class="mw-heading mw-heading2"><h2 id="Examples">Examples</h2></div>
<p>The basic built-in quantum data type in QCL is the qureg (quantum register). It can be interpreted as an array of qubits (quantum bits).
</p>
<div class="mw-highlight mw-highlight-lang-cpp mw-content-ltr" dir="ltr"><pre><span class="n">qureg</span><span class="w"> </span><span class="n">x1</span><span class="p">[</span><span class="mi">2</span><span class="p">];</span><span class="w"> </span><span class="c1">// 2-qubit quantum register x1</span>
<span class="n">qureg</span><span class="w"> </span><span class="n">x2</span><span class="p">[</span><span class="mi">2</span><span class="p">];</span><span class="w"> </span><span class="c1">// 2-qubit quantum register x2</span>
<span class="n">H</span><span class="p">(</span><span class="n">x1</span><span class="p">);</span><span class="w"> </span><span class="c1">// Hadamard operation on x1</span>
<span class="n">H</span><span class="p">(</span><span class="n">x2</span><span class="p">[</span><span class="mi">1</span><span class="p">]);</span><span class="w"> </span><span class="c1">// Hadamard operation on the first qubit of the register x2</span>
</pre></div>
<p>Since the qcl interpreter uses qlib simulation library, it is possible to observe the internal state of the quantum machine during execution of the quantum program.
</p>
<div class="mw-highlight mw-highlight-lang-text mw-content-ltr" dir="ltr"><pre>qcl&gt; dump
: STATE: 4 / 32 qubits allocated, 28 / 32 qubits free
0.35355 |0&gt; + 0.35355 |1&gt; + 0.35355 |2&gt; + 0.35355 |3&gt;
+ 0.35355 |8&gt; + 0.35355 |9&gt; + 0.35355 |10&gt; + 0.35355 |11&gt;
</pre></div>
<p>Note that the dump operation is different from measurement, since it does not influence the state of the quantum machine and can be realized only using a simulator.
</p><p>Like in modern programming languages, it is possible to define new operations which can be used to manipulate quantum data. For example:
</p>
<div class="mw-highlight mw-highlight-lang-cpp mw-content-ltr" dir="ltr"><pre><span class="k">operator</span><span class="w"> </span><span class="n">diffuse</span><span class="w"> </span><span class="p">(</span><span class="n">qureg</span><span class="w"> </span><span class="n">q</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">H</span><span class="p">(</span><span class="n">q</span><span class="p">);</span><span class="w"> </span><span class="c1">// Hadamard Transform</span>
<span class="w"> </span><span class="n">Not</span><span class="p">(</span><span class="n">q</span><span class="p">);</span><span class="w"> </span><span class="c1">// Invert q</span>
<span class="w"> </span><span class="n">CPhase</span><span class="p">(</span><span class="n">pi</span><span class="p">,</span><span class="w"> </span><span class="n">q</span><span class="p">);</span><span class="w"> </span><span class="c1">// Rotate if q=1111..</span>
<span class="w"> </span><span class="o">!</span><span class="n">Not</span><span class="p">(</span><span class="n">q</span><span class="p">);</span><span class="w"> </span><span class="c1">// undo inversion</span>
<span class="w"> </span><span class="o">!</span><span class="n">H</span><span class="p">(</span><span class="n">q</span><span class="p">);</span><span class="w"> </span><span class="c1">// undo Hadamard Transform</span>
<span class="p">}</span>
</pre></div>
<p>defines inverse about the mean operator used in <a href="Grover's_algorithm" title="Grover's algorithm">Grover's algorithm</a> (it is sometimes called <i>Grover's diffusion operator</i>). This allows one to define algorithms on a higher level of abstraction and extend the library of functions available for programmers.
</p>
<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>
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</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://tph.tuwien.ac.at/~oemer/qcl.html">"QCL - A Programming Language for Quantum Computers"</a>. <i>tuwien.ac.at</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2017-07-20</span></span>.</cite></span>
</li>
<li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><cite id="CITEREFÖmer2000" class="citation thesis cs1">Ömer, Bernhard (2000-01-20). <a rel="nofollow" class="external text" href="http://tph.tuwien.ac.at/~oemer/doc/quprog.pdf"><i>Quantum Programming in QCL</i></a> <span class="cs1-format">(PDF)</span> (Thesis). Institute for Theoretical Physics, Vienna University of Technology<span class="reference-accessdate">. Retrieved <span class="nowrap">2021-05-24</span></span>.</cite></span>
</li>
<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><cite id="CITEREFÖmer2003" class="citation journal cs1">Ömer, Bernhard (29 Apr 2003). "Classical Concepts in Quantum Programming". <i>International Journal of Theoretical Physics</i>. <b>44</b> (7): <span class="nowrap">943–</span>955. <a href="ArXiv_(identifier)" class="mw-redirect" title="ArXiv (identifier)">arXiv</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://arxiv.org/abs/quant-ph/0211100">quant-ph/0211100</a></span>. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1007%2Fs10773-005-7071-x">10.1007/s10773-005-7071-x</a>. <a href="S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a>&nbsp;<a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:119373370">119373370</a>.</cite></span>
</li>
<li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><cite id="CITEREFÖmer2009" class="citation web cs1">Ömer, Bernhard (2 September 2009). <a rel="nofollow" class="external text" href="http://tph.tuwien.ac.at/~oemer/doc/structquprog.pdf">"Structured Quantum Programming"</a> <span class="cs1-format">(PDF)</span>. Institute for Theoretical Physics, Vienna University of Technology.</cite></span>
</li>
<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://tph.tuwien.ac.at/~oemer/qcl.html">QCL web page</a></span>
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