Coherent storage and manipulation of broadband photons via dynamically controlled Autler-Townes splitting

The coherent control of light with matter, enabling storage and manipulation of optical signals, was revolutionized by electromagnetically induced transparency (EIT), which is a quantum interference effect. For strong electromagnetic fields that induce a wide transparency band, this quantum interference vanishes, giving rise to the well-known phenomenon of Autler-Townes splitting (ATS). To date, it is an open question whether ATS can be directly leveraged for coherent control as more than just a case of "bad" EIT. Here, we establish a protocol showing that dynamically controlled absorption of light in the ATS regime mediates coherent storage and manipulation that is inherently suitable for efficient broadband quantum memory and processing devices. We experimentally demonstrate this protocol by storing and manipulating nanoseconds-long optical pulses through a collective spin state of laser-cooled Rb atoms for up to a microsecond. Furthermore, we show that our approach substantially relaxes the technical requirements intrinsic to established memory schemes, rendering it suitable for broad range of platforms with applications to quantum information processing, high-precision spectroscopy, and metrology.Comment: 14 pages with 6 figures; 3 pages supplementary info with 2 supplementary figure

Single-photon-level light storage in cold atoms using the Autler-Townes splitting protocol

Broadband spin-photon interfaces for long-lived storage of photonic quantum states are key elements for quantum information technologies. Yet, reliable operation of such memories in the quantum regime is challenging due to photonic noise arising from technical and/or fundamental limitations in the storage-and-recall processes controlled by strong electromagnetic fields. Here, we experimentally implement a single-photon-level spin-wave memory in a laser-cooled Rubidium gas, based on the recently proposed Autler-Townes splitting (ATS) protocol. We demonstrate storage of 20-ns-long laser pulses, each containing an average of 0.1 photons, for 200 ns with an efficiency of $12.5\%$ and signal-to-noise ratio above 30. Notably, the robustness of ATS spin-wave memory against motional dephasing allows for an all-spatial filtering of the control-field noise, yielding an ultra-low unconditional noise probability of $3.3\times10^{-4}$, without the complexity of spectral filtering. These results highlight that broadband ATS memory in ultracold atoms is a preeminent option for storing quantum light.Comment: 6 pages, 4 figure

Incidence of kinesiophobia in patients with osteoarthritis knee an observational cross-sectional study

Background: The effects of kinesiophobia on pain perception in osteoarthritis patients have remained elusive. The intension of this study is to assess psychometric aspect of pain, functional activity, and kinesophobia in patients with chronic osteoarthritic knee pain. Methods: The study was time bound observational cross-section study, including 50 patients. Kinesiophobia was assessed using Tampa scale of kinesiophobia (TSK-11), while physical function and pain are assessed using WOMAC and VAS scores. Patients were included as per inclusion criteria in the OPD in Department of Orthopedics, AIIMS, Rishikesh, India. Results: It was observed 64% of patients were females while 36% were males. 46% patients had BMI range of 18.5-24.9, while 26% had BMI >=30, 20% had BMI between 25-29.9 and 8% of patients had BMI <18.5.  Mean BMI was 25.44±5.70 with minimum BMI of 14 and maximum BMI of 38. It was observed female patients mean WOMAC score was 44.44±19.41, while mean VAS score 4.25±1.05 and mean TSK-11was 33.34±12.57, male patients mean WOMAC score was 35.39±13.62 while mean VAS score was 4.39±0.92, mean TSK-11 was 35.78±14.52. It was observed that there was no substantial difference on basis of gender in all three parameters when compared.  This study suggests, there was no significant association between Age and VAS score (p-value 0.017) with Pearson correlation of 0.335. Conclusions: Prospective therapies for kinesiophobia should attempt to reduce pain intensity and functionality improvement