Simulating Quantum Spin Models with Laser-Cooled Molecules in Optical Tweezer Arrays

Princeton University, Princeton NJ

Investigators

Abstract

Quantum mechanics plays a central role in many questions in physics ranging from how blackholes behave to why magnets exist. Although the quantum mechanics of isolated single particles is well-understood and has led to a wide variety of modern-day technologies such as lasers and atomic clocks, systems of interacting quantum particles are not nearly as well-understood. Such systems offer interesting possibilities such as exhibiting superconductivity or forming the basis of quantum computers, but the properties of interacting quantum systems are difficult to predict and in many cases are beyond the capabilities of the most powerful computers. To address this challenge, the research team will build a novel “quantum simulator” based on molecules at ultracold temperatures held by focused laser beams. The platform will harness quantum interactions inherent to molecules to explore a variety of interacting quantum models. These explorations could not only improve our understanding of complex quantum systems, but potentially provide new insight for practical applications such as novel quantum materials and quantum-enhanced sensors. In addition, the research has direct societal impact through the training of graduate and undergraduate students. With the ever-growing societal focus on quantum science and its promises, the research effort will contribute to building a quantum-literate workforce in industry, national labs and academia. Models of interacting quantum spins have deep connections to many diverse areas of physics. Various spin models can capture the magnetic behavior of real-life materials or even mimic properties of blackholes. A key challenge in studying large-scale spin systems is predicting their resulting quantum dynamics, which is often beyond the reach of state-of-the-art theory. While some spin models can be experimentally explored using existing quantum platforms based on neutral atoms and ions, the variety of accessible models is limited. To address this limitation, the research team will develop a novel quantum simulator leveraging two nascent technologies, laser-cooled molecules and programmable arrays of optical tweezer traps. By mapping quantum spins to the quantum rotations of molecules, and using the inherent electric dipolar interactions between molecules, the molecule-based quantum simulator could provide access to a variety of long-ranged interacting spin models in intermediate-sized arrays. Specifically, the team will 1) develop the necessary building blocks of the new molecule-based quantum simulator, which include developing methods to initialize and detect large arrays of molecules; and 2) create and verify effective long-range spin-spin interactions in 1D molecular arrays. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.