作者报道了首次通过冷却激光辐射负离子。通过选择性地分离最热的粒子，将O-离子限制在线性保罗阱中进行冷却。 为此，用532 nm激光以最大径向偏移照射总能量最高的负离子。利用激光-粒子相互作用，实现了更冷和更密集的离子云，实现了从1.15到0.33eV三倍以上的温度降低。与稀释缓冲气体的相互作用相比，负离子的能量选择性处理和去除导致最终温度降低，同时，反应速度加快了10倍， 在最终状态下保留了两倍多的离子。 一组冷负离子能够提供冷却任何其他负离子能力，从而能够促进从星际化学到反物质重力的广泛基础研究。该技术可以扩展到任何可以通过光分离完成中性化的负离子。

        图1：线性保罗阱的示意图。从左侧进入陷阱，然后向右向MCP检测器出口。

This research is published in Physical Review Letters.

Reference

[1] J.-S.Chen,S.M.Brewer,C.W.Chou,D.J.Wineland,D.R. Leibrandt, and D.B. Hume, Phys. Rev. Lett. 118, 053002 (2017).

[2] W. Rosenfeld, D. Burchardt, R. Garthoff, K. Redeker, N. Ortegel, M. Rau, and H. Weinfurter, Phys. Rev. Lett. 119, 010402 (2017).

[3] N. Friis, O. Marty, C. Maier, C. Hempel, M. Holzäpfel, P. Jurcevic, M.B. Plenio, M. Huber, C. Roos, R. Blatt et al., Phys. Rev. X 8, 021012 (2018).

[4] M.H. Anderson, J.R. Ensher, M.R. Matthews, C.E. Wieman, and E.A. Cornell, Science 269, 198 (1995).

[5] K.B. Davis, M.-O. Mewes, M.R. Andrews, N.J. van Druten, D.S. Durfee, D.M. Kurn, and W. Ketterle, Phys. Rev. Lett. 75, 3969 (1995).

[6] M. Drewsen, Physica (Amsterdam) 460B, 105 (2015).

[7] L. Schmöger, O.O. Versolato, M. Schwarz, M. Kohnen, A. Windberger, B. Piest, S. Feuchtenbeiner, J. PedregosaGutierrez, T. Leopold, P. Micke et al., Science 347, 1233 (2015).

[8] W.G. Rellergert, S.T. Sullivan, S.J. Schowalter, S. Kotochigova, K. Chen, and E.R. Hudson, Nature (London) 495, 490 (2013).

[9] B. Höltkemeier, P. Weckesser, H. López-Carrera, and M. Weidemüller, Phys. Rev. Lett. 116, 233003 (2016).

[10] A. Kellerbauer and J. Walz, New J. Phys. 8, 45 (2006).

[11] A. Kellerbauer et al. (AEGIS Proto-Collaboration), Nucl. Instrum. Methods B 266, 351 (2008).

[12] U. Warring, M. Amoretti, C. Canali, A. Fischer, R. Heyne, J.O. Meier, C. Morhard, and A. Kellerbauer, Phys. Rev. Lett. 102, 043001 (2009).

[13] C.W. Walter, N.D. Gibson, Y.-G. Li, D.J. Matyas, R.M. Alton, S.E.Lou, R.L.Field, D.Hanstorp, L.Pan,and D.R. Beck, Phys. Rev. A 84, 032514 (2011). [14] P. Yzombard, M. Hamamda, S. Gerber, M. Doser, and D. Comparat, Phys. Rev. Lett. 114, 213001 (2015).

[15] S. Gerber, J. Fesel, M. Doser, and D. Comparat, New J. Phys. 20, 023024 (2018).

[16] S.M. O’Malley and D.R. Beck, Phys. Rev. A 81, 032503 (2010).

[17] C.W. Walter, N.D. Gibson, D.J. Matyas, C. Crocker, K.A. Dungan, B.R. Matola, and J. Rohl´en, Phys. Rev. Lett. 113, 063001 (2014).

[18] E. Jordan, G. Cerchiari, S. Fritzsche, and A. Kellerbauer, Phys. Rev. Lett. 115, 113001 (2015).

[19] G. Cerchiari, A. Kellerbauer, M.S. Safronova, U.I. Safronova, and P. Yzombard, Phys. Rev. Lett. 120, 133205 (2018).

[20] A. Crubellier, J. Phys. B 23, 3585 (1990).

[21] W. Ketterle and N.J. Van Druten, Adv. At. Mol. Opt. Phys. 37, 181 (1996). [22] B.M. Penetrante, J.N. Bardsley, M.A. Levine, D.A. Knapp, and R.E. Marrs, Phys. Rev. A 43, 4873 (1991).

[23] W.Chaibi, R.J.Pelaez,C.Blondel,C.Drag,andC.Delsart, Eur. Phys. J. D 58, 29 (2010).