High-angular-momentum Rydberg states in a room-temperature vapor cell for dc electric-field sensing

Abstract

We prepare and analyze Rydberg states with orbital quantum numbers <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mi>ℓ</a:mi><a:mo>≤</a:mo><a:mn>6</a:mn></a:mrow></a:math> using three-optical-photon electromagnetically induced transparency (EIT) and radio frequency (rf) dressing, and employ the high-<b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mi>ℓ</b:mi></b:math> states in electric-field sensing. Rubidium-85 atoms in a room-temperature vapor cell are first promoted into the <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mn>25</c:mn><c:msub><c:mi>F</c:mi><c:mrow><c:mn>5</c:mn><c:mo>/</c:mo><c:mn>2</c:mn></c:mrow></c:msub></c:mrow></c:math> state via Rydberg-EIT with three infrared laser beams. Two rf dressing fields then (near-)resonantly couple the <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:mn>25</d:mn><d:mi>F</d:mi></d:mrow><d:mo>,</d:mo><d:mo> </d:mo><d:mrow><d:mn>25</d:mn><d:mi>H</d:mi><d:mspace width="0.16em"/><d:mo>(</d:mo><d:mi>ℓ</d:mi><d:mo>=</d:mo><d:mn>5</d:mn><d:mo>)</d:mo></d:mrow></d:math>, and <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mrow><f:mn>25</f:mn><f:mi>I</f:mi><f:mspace width="0.16em"/><f:mo>(</f:mo><f:mi>ℓ</f:mi><f:mo>=</f:mo><f:mn>6</f:mn><f:mo>)</f:mo></f:mrow></f:math> Rydberg states. The dependence of the rf-dressed Rydberg-state level structure on rf powers, rf and laser frequencies is characterized using EIT. Furthermore, we discuss the principles of dc-electric-field sensing using high-<h:math xmlns:h="http://www.w3.org/1998/Math/MathML"><h:mi>ℓ</h:mi></h:math> Rydberg states and experimentally demonstrate the method using test electric fields of <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"><i:mo>≲</i:mo><i:mn>50</i:mn></i:math> V/m induced via photo-illumination of the vapor-cell wall. We measure the highly nonlinear dependence of the dc-electric-field strength on the power of the photo-illumination laser. Numerical calculations, which reproduce our experimental observations well, elucidate the underlying physics. Our paper is relevant to high-precision spectroscopy of high-<j:math xmlns:j="http://www.w3.org/1998/Math/MathML"><j:mi>ℓ</j:mi></j:math> Rydberg states, Rydberg-atom-based electric-field sensing, and plasma electric-field diagnostics. Published by the American Physical Society 2024