AUTHOR=Puentes Graciana , Banerji Anindya 

TITLE=Generation of High-Order Vortex States From Two-Mode Squeezed States

JOURNAL=Frontiers in Physics

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2021.690721

DOI=10.3389/fphy.2021.690721

ISSN=2296-424X

ABSTRACT=<p>We report a scheme for generation of high-order quadrature vortex states using two-mode photon-number squeezed states, generated via the non-linear process of Spontaneous Parametric Down Conversion. By applying a parametric rotation in the quadratures <inline-formula id="inf1"><mml:math id="m1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:mrow><mml:mover accent="true"><mml:mi>X</mml:mi><mml:mo stretchy="true">^</mml:mo></mml:mover></mml:mrow><mml:mo>,</mml:mo><mml:mrow><mml:mover accent="true"><mml:mi>Y</mml:mi><mml:mo stretchy="true">^</mml:mo></mml:mover></mml:mrow></mml:mrow><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math></inline-formula>, using a ϕ converter, the Gaussian profile of the photon-number squeezed input state can be mapped into a superposition of Laguerre-Gauss modes in the quadratures with <italic>N</italic> vortices or singularities, for an input state containing <inline-formula id="inf2"><mml:math id="m2" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>2</mml:mn><mml:mi>N</mml:mi></mml:mrow></mml:math></inline-formula> photons, thus mapping photon-number fluctuations to interference effects in the quadratures. Our scheme has the potential to improve measurement sensitivity beyond the Standard uantum Limit (SQL <inline-formula id="inf3"><mml:math id="m3" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>∝</mml:mo><mml:msqrt><mml:mi>N</mml:mi></mml:msqrt></mml:mrow></mml:math></inline-formula>), by exploiting the advantages of optical vortices, such as high dimensionality or topological properties, for applications requiring reduced uncertainty, such as quantum cryptography, quantum metrology and sensing.</p>