Electromagnetically induced transparency based Rydberg-atom sensor for traceable voltage measurements

Abstract

We investigate the Stark shift in Rydberg rubidium atoms through electromagnetically induced transparency for the measurement of direct current (dc) and 60 Hz alternating current (ac) voltages. This technique has direct application to the calibration of voltage measurement instrumentation. We present experimental results for different atomic states that allow for dc and ac voltage measurements ranging from 0 to 12 V. While the state-of-the-art method for realizing the volt, the Josephson voltage standard, is significantly more accurate, the Rydberg atom-based method presented here has the potential to be a calibration standard with more favorable size, weight, power, and cost. We discuss the steps necessary to develop the Rydberg atom-based voltage measurement as a complementary method for dissemination of the voltage scale directly to the end user and discuss sources of uncertainties for these types of experiments.

Quantum sensing of microwave electric fields based on Rydberg atoms

“…In 2012, researchers from the University of Oklahoma and the University of Stuttgart first demonstrated MW E-field sensing at a frequency of 14.23 GHz by AT splitting of the EIT spectrum with a 5S 1/2 → 5P 3/2 → 53D 5/2 → 54P 3/2 four-level 85 Rb atomic coherent system [12]. The diagram of the energy level and experimental setup of this system are shown in figure 5.…”

“…The PPWG antenna radiates an LO field, and a more important function is that it can capture the RF field arriving from a remote location and concentrate it at the location of the atomic vapor cell for detection. The embedding of two stainless-steel parallel plates inside the vapor cell allows the measurement of DC and 60 Hz AC voltages with more favorable size, weight, power and cost [85]. The recent use of a sub-wavelength split-ring resonator (SRR) incorporated with an atomic vapor cell provides 100 times enhancement of the E-field measurement sensitivity.…”

“…Moreover, it is worth mentioning that the transition between adjacent Rydberg circular states has the largest transition dipole moment, and the Rydberg circular state has the longest radiation lifetime under the same principal quantum number [98]. Recently, it has been shown experimentally that a Rydberg circular state 85 Rb atom system with n = 60 obtained a lifetime of more than 1 ms at room temperature [99]. Therefore, based on the Rydberg circular state system, the sensitivity approaching the projection noise limit allowed by the atomic system can be predicted.…”

“…Schematic diagrams of resonance cavities. (a) Four-mirror ring optical resonator[81], (b) microelectromechanical system vapor cell[82], (c) PPWG[84], (d) integrated PPWG[85] and (e) SRR[86].…”

Frequency modulation of Rydberg states by radio frequency electromagnetic fields

“…Rydberg atomic systems equipped with an appropriate energy spectrum-probing method have made precision radio-frequency (RF) electrometry and magnetometry possible. Atomic states can be modulated by external oscillating fields; for Rydberg states, this modulation is especially strong because of the crucial dependency of the dipole moment and polarizability on n. [5][6][7] Over the past couple of decades, [8][9][10] Rydberg Stark spectrum has been investigated for rubidium using electromagnetically induced transparency (EIT). EIT, as an energy spectrum-probing technique, allows one to probe very sharp energy features in the spectrum with accuracy.…”