Research

After the successful demonstration of the Bose-Einstein condensate (BEC), experimentalists have achieved remarkable control over the system setup, such as the magneto-optical configuration, and system parameters, including atom-atom interactions. Specifically, the interactions between atoms, both within the same species and between different species in the case of coupled condensates, can be finely tuned using Feshbach resonance. This breakthrough has opened up unique opportunities to explore various phenomena in quantum optics, condensed matter physics, and high-energy physics that are challenging to observe in their natural contexts. In the realm of quantum optics, the BEC provides a platform to investigate phenomena such as light-matter interactions and superradiance. The precise control over the BEC setup enables researchers to study the intricate dynamics of how light interacts with matter at the quantum level. Additionally, the collective emission of radiation known as superradiance can be observed in BECs, where an ensemble of atoms emits radiation in a coherent and amplified manner. The successful realization of the BEC and the subsequent control over system parameters have opened up exciting avenues for studying various phenomena in quantum optics, condensed matter physics, and high-energy physics. The BEC system serves as a powerful tool for investigating complex phenomena that are typically challenging to observe in their natural contexts.

• Ultra-cold Atomic Gasses

Our research group focuses on investigating the dynamics and characteristics of ultra-cold atoms and Bose-Einstein condensates (BEC). We utilize simulations to study various phenomena associated with BECs, such as the negative mass regime, bound state formation, and the generation of nonlinear resonances. To analyze these phenomena, our group employs the standard mean-field approach, utilizing the self-similar/F-expansion method to obtain analytical results. It is worth highlighting that the nonlinearity arising from the atom-atom interactions in BECs bears similarities to the Kerr-type nonlinearity observed in optics. As a result, the periodic excitations and solitons observed in our studies have significant applications in the field of nonlinear optics and fiber optics. These findings can play a crucial role in enhancing optical communication systems. By investigating the dynamics and properties of ultra-cold atoms and BECs, our research group aims to deepen our understanding of fundamental physics and explore potential applications in nonlinear optics and communication technologies. Through our simulations and analytical methods, we strive to contribute to the advancement of knowledge in these fields and pave the way for practical implementations in various areas of science and technology.

• Superradiance and Quantum Phase Transition

Our research group is actively engaged in studying light-matter interactions, specifically focusing on superradiance and quantum phase transitions. These areas of research have significant implications in the fields of quantum computing and quantum information theory. In order to build a quantum computer, it is crucial to have a method to initialize a group of qubits, or quantum bits, so that they are all in the same state. Bose-Einstein condensates (BECs) offer a promising platform for this purpose as they consist of a macroscopic number of atoms occupying the same quantum state. The unique characteristics of BECs make them well-suited for quantum computing applications. Our investigations into the superradiant phase transition of BECs have direct implications for the study of N-particle entanglement. This research has recently been published in the esteemed journal New Journal of Physics and has garnered considerable attention from the cold atoms and quantum optics community. It is worth mentioning that Professor W. Ketterle from MIT, who was awarded the Nobel Prize in 2001 for his groundbreaking experimental realization of the BEC, has expressed appreciation for our work through a personal email. This recognition highlights the significance of our research in opening up new possibilities for studying the transfer of entanglement or entanglement swapping. By exploring the dynamics of light-matter interactions in BECs and investigating quantum phase transitions, our group aims to advance our understanding of fundamental physics and contribute to the development of quantum computing and quantum information theory. The recognition and attention our work has received serve as strong indicators of the relevance and impact of our research in the scientific community.

• Analogue Gravity Models

One intriguing application of Bose-Einstein condensates (BEC) is their use as a tool to study analog gravity models and ultra-cold chemistry. Analog gravity models involve creating analogues of black holes in laboratory settings using BECs. Scientists achieve this by confining the BEC in a step-like potential, simulating the presence of an event horizon. Through these experiments, researchers can explore various aspects of black hole physics, including predicting the Hawking temperature, associated space-time curvature, and the entanglement between particles inside (partner particles) and outside (Hawking radiation) the event horizon.  

• Ultra-cold Chemistry

The creation and manipulation of cold molecules from atomic BECs have opened up new avenues for studying chemical reactions at ultra-low temperatures, known as "super-chemistry." This field is immensely valuable for exploring the quantum control of matter-wave reactions in extremely cold environments. Our research group focuses on coherent quantum state transfer from atomic to molecular condensates through atom-molecular inter-conversion. We also investigate the cooperative many-body effects of photo-association on Lieb modes through molecular dispersion. 

• Plasmonics

In addition to our work in analog gravity models and ultra-cold chemistry, our group is actively engaged in studying nanoscale quantum plasmonics. Specifically, we are investigating the entanglement properties of pulses reflected and transmitted from an optical cavity. Nonclassicality is introduced through the second harmonic generation (SHG) of a metal nanoparticle (MNP) coupled to a quantum dot within the cavity. The SHG of the MNP is enhanced by path interference effects, such as Fano resonance, bringing the nonlinear process into resonance or enhancing it.

These research endeavors in analog gravity models, ultra-cold chemistry, and quantum plasmonics demonstrate the diverse and interdisciplinary nature of our group's work. By harnessing the unique properties of BECs and exploring their applications in different fields, we aim to contribute to the advancement of knowledge in quantum physics, chemistry, and nanotechnology.