Key Publications

1. Numerical simulation of Rydberg-Rydberg interaction strengths and dipole blockade radii in the presence of Förster resonances,

Opt. Express 31, 37094 (2023).

• • Significance for the Academic Profile: We present a numerical simulation to achieve a substantial blockade radius, which is critical for the development of scalable and efficient quantum communication and computation. In this theoretical study, we propose a method to enhance the Rydberg blockade radius by leveraging Förster resonance. This phenomenon arises when the energy difference between two initial Rydberg states closely matches that between the corresponding final Rydberg states, leading to a resonant energy transfer process. We employ quantum defect theory to perform a numerical calculation for the 87Rb–87Rb Rydberg atomic pair, allowing us to accurately estimate the van der Waals interaction. Our investigation reveals that when the principal quantum numbers of the two Rydberg atomic pairs differ only slightly, the Förster transition rarely results in a significant blockade radius. However, in cases where the principal quantum numbers differ significantly, we demonstrate a substantial improvement in the Rydberg blockade radius. Most notably, we identify transition channels that exhibit an extensive crossover blockade radius, exceeding 50 μm. This notable increase in the blockade radius not only facilitates larger-scale quantum operations but also advances quantum technologies, with broad implications for achieving long-range quantum entanglement and robust quantum processes.

2. High-contrast thermal atomic Rydberg EIT spectroscopy measurement and applications,

 Opt. Express 30, 1499 (2022) and J. Appl. Phys. 132, 244401 (2022). 

• • Significance for the Academic Profile: The atomic transitions involving Rydberg state n>>1 can be applied for the precision measurement of microwave electrometry. A probe (Ωp) and a coupling (Ωc) fields form a typical cascade transition, and an additional optical pumping field pumps the population from |g1⟩ to |g2⟩ state. Based on the measurements, the EIT peak height exhibits a potential for a twofold improvement or a reduction by one order of magnitude. The quantitative prediction of the EIT feature is achieved through a Doppler-free, non-perturbative numerical calculation. In both simulations and measurements, the enhancement or reduction of Rydberg-EIT via optical pumping (OP) depends on the probe field's intensity and the optical density. Our research elucidates the fundamental mechanisms of optical pumping, rendering related studies valuable in advancing the field of Rydberg-based electrometry.

3. Investigation of atomic diffusion characteristics through microchannels,

Phys. Fluids 34, 072004 (2022).

• • Significance for the Academic Profile: Microchannels filled with gas have been employed to achieve extremely low-light-level nonlinear interactions between matter and light. In this study, we explore the diffusion dynamics of Rb vapors within microscale channels. Following the Knudsen diffusion model, the transport time for the case under investigation is estimated to be in the order of minutes, which is five orders of magnitude shorter than the actual experimental observations. We delve into factors such as coating time and dwell time that could potentially affect the slow diffusion, along with the gas flow rate at different vapor temperatures. By examining the temporal evolution of atomic density, we calculate that the dwell times within the uncoated quartz capillary were 17 ms, 28 ms, and 11 ms for temperatures of 40°C, 60°C, and 74°C, respectively. 

4. Coherent Optical Memory with High Storage Efficiency and Large Fractional Delay,

Phys. Rev.Lett. 110, 083601 (2013).  

• • Significance for the Academic Profile: Using a time-space-reversing method plus optimum pulse shape, we stored and retrieved of an incident pulse with an efficiency up to 78%. A fractional delay of 74 shows the memory can potentially provide a delay time of 74-bit operations. Our work significantly advances the technology of optical memory and may find practical applications in quantum communication. 

5. Demonstration of the Interaction between Two Stopped Light Pulses,

Phys. Rev. Lett. 108, 173603 (2012). 

• • Significance for the Academic Profile: We experimentally demonstrated the photon switch efficiency has a 4-folds enhancement in the scheme of the stored light switched by stationary light. The study was quoted by Research Highlights of Nature Physics 8, 252 (2012) as a title of Frozen light switch and Featured Story of Phys.org as a title of Two stopped light pulses interact with each other.

6. Large Cross-Phase Modulations at the Few-Photon Level,

Phys. Rev. Lett. 117, 203601 (2016). (Editor's suggestion, Featured in Physics)

• • Significance for the Academic Profile: One photon controls the other photon by a phase of pi is the requirements of a deterministic and universal quantum logic gate. We employ a double-EIT system and observe 3.6 radians induced by a light pulse containing 8 photons. The photon phase shift is not limited by the interacting photons number, and in principle, the scheme can reach the goal of pi phase shift by a single photon. 

7. Pulsed Rydberg four-wave mixing with motion-induced dephasing in a thermal vapor,

 Appl. Phys. B 122(1), 1-6 (2016) and Phys. Rev. A 93, 053429 (2016). 

• • Significance for the Academic Profile: We were the first group investigating the properties of Rydberg polaritons in a thermal vapor, including the polaritons lifetime. The theoretical calculation needs to take into account the spatial profiles of the laser beams in the resonant Rydberg FWM transition. The simulation plays a significant role in our following research on a high NA optical alignment and single-photon generation via a single Rydberg FWM transition. I am the corresponding authors in these two papers. 

8. Fidelity of the electromagnetically-induced-transparency-based optical memory,

 Phys. Rev. A 88, 023805 (2013).

• • Significance for the Academic Profile: A resolution of two-photon detuning was higher than 10 kHz in an EIT system. The sensitivity cnn be further improved to be 30 mHz by observing the storage-time-dependent phase shift. Our technique benefits the study in the high-precision spectroscopy. In addition, the method can be used for the detection of the magnetic field gradient as a high-sensitive magnetometer. We can well control the field gradient and compensate the value as low as 2 mG/cm.