Quantum Optical Spanner: Twisting Superconductors with Vortex Beam via Higgs Mode (2504.11883v1)

Abstract: Light carrying orbital angular momentum (OAM)--known as vortex beams--has broadened the scope of understanding and applications of light's angular momentum. Optical tweezers using OAM, often referred to as optical spanners, have significantly expanded the tunability of optical manipulation. A key frontier now lies in understanding how vortex beams interact with quantum states of matter. In this work, we numerically investigate the dynamics of a superconductor under vortex beam illumination and demonstrate the transfer of angular momentum from light to the superconducting collective mode, resulting in mechanical rotation. Our findings open a pathway for optical manipulation in the quantum regime, which we term the quantum optical spanner.

Quantum Optical Spanner: Twisting Superconductors with Vortex Beam via Higgs Mode

The paper "Quantum Optical Spanner: Twisting Superconductors with Vortex Beam via Higgs Mode" by Kang, Kitamura, and Morimoto introduces a novel method of manipulating superconductors using light carrying orbital angular momentum (OAM). This work investigates the interaction between vortex beams, which are light beams that carry OAM, and superconducting materials. The paper examines how angular momentum can be transferred from the vortex beam to the superconducting collective mode, inducing mechanical rotation.

Key Findings

The authors utilize numerical simulations of the time-dependent Ginzburg-Landau (TDGL) equation to explore the dynamics of superconductors subjected to vortex beam illumination. It was observed that the vortex beam can effectively transfer angular momentum to superconductors via the excitation of Higgs modes. This signifies a unique mechanism wherein optical OAM can be converted to mechanical angular momentum inside quantum matter, and these findings pave the way for non-contact manipulation of quantum materials using the quantum optical spanner methodology.

Methodology

The authors apply the TDGL equation to model the dynamics of superconducting order parameters in the presence of vortex beams. They employ the LG beams to simulate these vortex beams, characterized by their distinct spatial profiles—the helical phase front and ring-shaped intensity distribution—which are crucial for carrying OAM. The investigation includes varying parameters such as the OAM $l$ and radial index $p$ of the LG beams, to evaluate their impact on angular momentum transfer to the superconductor.

Implications and Future Work

The consequent angular momentum transfer measured in the superconductors highlights potential applications in manipulating quantum matter. This paper could lead to innovations in optical technologies, as well as advancements in fields such as quantum computing and nano-scale materials manipulation. The results suggest that rotational motion can be induced in superconductors at feasibly measurable frequencies, given sufficient laser field strength, opening up possibilities for practical experiments.

Furthermore, the delineation of angular momentum transfer through Higgs excitation broadens our understanding of coherent quantum phenomena involving condensed-matter systems. This could have implications for developing techniques to control quantum states in superconductors and related materials.

Concluding Remarks

This paper highlights the transformative potential of vortex beams in quantum manipulation, demonstrating experimentally viable conditions for angular momentum transfer in superconductors. The exchange of angular momentum mediated by vortex beams provides a promising avenue for exploring quantum optical manipulation and contributes significantly to the field of quantum optics in solid-state systems. Future research may focus on extending these findings to other quantum states of matter, or on refining techniques for more efficient transfers of angular momentum in practical applications.