Raman Quantum Memory with Built-In Suppression of Four-wave Mixing Noise

(2019)

Authors:

Sarah E Thomas, Thomas M Hird, Joseph HD Munns, Benjamin Brecht, Dylan J Saunders, Joshua Nunn, Ian A Walmsley, Patrick M Ledingham

Noise suppression via atomic absorption in a Raman quantum memory

Quantum Information and Measurement (QIM) V: Quantum Technologies, OSA Technical Digest (Optical Society of America, 2019) OSA Publishing (2019)

Authors:

Tm Hird, SE Thomas, JHD Munns, B Brecht, DJ Saunders, J Nunn, IA Walmsley, Patrick Ledingham

Abstract:

We demonstrate strong suppression of noise on the output of a Raman quantum memory.

Probing multiple-frequency atom-photon interactions with ultracold atoms

(2018)

Authors:

Kathrin Luksch, Elliot Bentine, Adam J Barker, Shinichi Sunami, Tiffany L Harte, Ben Yuen, Christopher J Foot

Engineering a noiseless and broadband Raman quantum memory for temporal mode manipulation

Frontiers in Optics / Laser Science Part F114-FIO 2018 (2018)

Authors:

TM Hird, Sarah THOMAS, JOSEPH MUNNS, J Nunn, Oscar Arjona, Shabo Gao, Benjamin Brecht, PM Ledingham, IAN WALMSLEY

Abstract:

© 2018 The Author(s). The Raman quantum memory can manipulate temporal modes of light - a promising high-dimensional basis for quantum information processing. We demonstrate both temporal mode manipulation and a novel suppression scheme for four-wave mixing noise.

Two-frequency operation of a Paul trap to optimise confinement of two species of ions

International Journal of Mass Spectrometry Elsevier (2018)

Authors:

Christopher Foot, D Trypogeorgos, E Bentine, A Gardner, M Keller

Abstract:

© 2018 Elsevier B.V. We describe the operation of an electrodynamic ion trap in which the electric quadrupole field oscillates at two frequencies. This mode of operation allows simultaneous tight confinement of ions with extremely different charge-to-mass ratios, e.g., singly ionised atomic ions together with multiply charged nanoparticles. We derive the stability conditions for two-frequency operation from asymptotic properties of the solutions of the Mathieu equation and give a general treatment of the effect of damping on parametric resonances. Two-frequency operation is effective when the two species’ mass ratios and charge ratios are sufficiently large, and further when the frequencies required to optimally trap each species are widely separated. This system resembles two coincident Paul traps, each operating close to a frequency optimised for one of the species, such that both species are tightly confined. This method of operation provides an advantage over single-frequency Paul traps, in which the more weakly confined species forms a sheath around a central core of tightly confined ions. We verify these ideas using numerical simulations and by measuring the parametric heating induced in experiments by the additional driving frequency.