[논문 리뷰] Tune-out wavelength for the thulium atom near 576 nm

Ivan Pyrkh, Arjuna Rudnev외 13명|arXiv (Cornell University)|2026. 02. 24.

Cold Atom Physics and Bose-Einstein Condensates인용 수 0

한 줄 요약

논문은 근상 톨루미움의 tune-out 파장을 576 nm 부근에서 이론적으로 예측하고 이를 실험적으로 측정하여 polarizability가 0이 되는 지점을 확인하고, 특정 좁은 파장 범위에서 Bose-Einstein condensation을 가능하게 한다.

ABSTRACT

We report the theoretical prediction and measurement of a tune-out wavelength for the ground state of the thulium atom in a linearly polarized optical dipole trap with a wavelength of approximately 576 nm. The measurements were conducted using a combination of trap frequency and RF loss spectroscopy, thus making it possible to separate the scalar and tensor parts of the total polarizability without measurements in the range of negative total polarizability. The calculated tune-out wavelength is consistent with the measured one of $575.646_{-0.014}^{+0.016}$ nm in air. The existence of the zero in the polarizability for the Tm ground state was confirmed by the trap loss experiment, which also made it possible to refine the tune-out wavelength to $575.646_{-0.004}^{+0.004}$. Despite the presence of an imaginary part of the polarizability at some wavelengths, it was experimentally demonstrated that, with a proper choice of the dipole trap polarization, it was possible to achieve Bose-Einstein condensation of thulium atoms in the range from 575.348 to 575.689 nm, covering the tune-out wavelength.

연구 동기 및 목표

• Identify the tune-out wavelength where the thulium ground-state polarizability vanishes in a linearly polarized trap.
• Separate scalar and tensor contributions to the total polarizability without traversing negative polarizability regimes.
• Validate the predicted tune-out wavelength with trap-frequency and RF loss spectroscopy.
• Refine the tune-out wavelength and demonstrate BEC in a wavelength window around the tune-out point.

제안 방법

• Combine trap-frequency measurements with RF loss spectroscopy to extract polarizability components.
• Use analysis that isolates scalar and tensor parts of polarizability in a 576 nm trap.
• Demonstrate Bose-Einstein condensation of thulium across a polarization-optimized dipole trap.
• Compare measured tune-out wavelength to theoretical prediction and refine its value.

실험 결과

연구 질문

• RQ1 What is the tune-out wavelength for the ground-state thulium atom in a linearly polarized trap near 576 nm?
• RQ2 Can scalar and tensor components of the total polarizability be separated without crossing negative polarizability regimes?
• RQ3 Does the zero in polarizability occur within experimental uncertainty, and how does it align with theory?
• RQ4 Can thulium Bose-Einstein condensation be achieved within a trap range that includes the tune-out wavelength by choosing appropriate polarization?

주요 결과

• The calculated tune-out wavelength is consistent with the measured value 575.646_{-0.014}^{+0.016} nm in air.
• The trap loss experiment confirms the existence of a zero in polarizability for the Tm ground state.
• The tune-out wavelength is refined to 575.646_{-0.004}^{+0.004} nm.
• Bose-Einstein condensation of thulium is demonstrated in a dipole-trap range from 575.348 to 575.689 nm, encompassing the tune-out wavelength.
• An appropriate choice of dipole-trap polarization allows condensation despite the imaginary part of polarizability at some wavelengths.