Publications


Strong coupling of a single ion to an optical cavity

Physical Review Letters American Physical Society 124 (2020) 013602

H Takahashi, E Kassa, C Christoforou, M Keller

Strong coupling between an atom and an electromagnetic resonator is an important condition in cavity quantum electrodynamics. While strong coupling in various physical systems has been achieved so far, it remained elusive for single atomic ions. Here, we achieve a coupling strength of 2π × ð12.3 0.1Þ MHz between a single 40Caþ ion and an optical cavity, exceeding both atomic and cavity decay rates which are 2π × 11.5 and 2π × ð4.1 0.1Þ MHz, respectively. We use cavity assisted Raman spectroscopy to precisely characterize the ion-cavity coupling strength and observe a spectrum featuring the normal mode splitting in the cavity transmission due to the ion-cavity interaction. Our work paves the way towards new applications of cavity quantum electrodynamics utilizing single trapped ions in the strong coupling regime for quantum optics and quantum technologies.


Roadmap on STIRAP applications

Journal of Physics B: Atomic, Molecular and Optical Physics IOP Publishing (2019)

K Bergmann, HC Naegerl, C Panda, A Kuhn


Polarisation Oscillations in Birefringent Emitter-Cavity Systems

Physical Review Letters American Physical Society (2019)

TD Barrett, O Barter, D Stuart, B Yuen, A Kuhn

We present the effects of resonator birefringence on the cavity-enhanced interfacing of quantum states of light and matter, including the first observation of single photons with a time-dependent polarisation state that evolves within their coherence time. A theoretical model is introduced and experimentally verified by the modified polarisation of temporally-long single photons emitted from a $^{87}$Rb atom coupled to a high-finesse optical cavity by a vacuum-stimulated Raman adiabatic passage (V-STIRAP) process. Further theoretical investigation shows how a change in cavity birefringence can both impact the atom-cavity coupling and engender starkly different polarisation behaviour in the emitted photons. With polarisation a key resource for encoding quantum states of light and modern micron-scale cavities particularly prone to birefringence, the consideration of these effects is vital to the faithful realisation of efficient and coherent emitter-photon interfaces for distributed quantum networking and communications.


Multimode interferometry for entangling atoms in quantum networks

Quantum Science and Technology IOP Publishing (2019)

TD Barrett, A Rubenok, D Stuart, O Barter, A Holleczek, J Dilley, P Nisbet-Jones, K Poulios, G Marshall, J O'Brien, A Politi, J Matthews, A Kuhn


Benchmarking modern algorithms to holographically create optical tweezers for laser-cooled atoms

JOURNAL OF MODERN OPTICS 65 (2018) 2133-2141

N Holland, D Stuart, O Barter, A Kuhn


Nonlinear Zeeman effects in the cavity-enhanced emission of polarised photons

NEW JOURNAL OF PHYSICS 20 (2018) ARTN 073030

TD Barrett, D Stuart, O Barter, A Kuhn


Precise positioning of an ion in an integrated Paul trap-cavity system using radiofrequency signals

Journal of Modern Optics Informa UK Limited 65 (2018) 520-528

E Kassa, H Takahashi, C Christoforou, M Keller


Single-atom trapping and transport in DMD-controlled optical tweezers

NEW JOURNAL OF PHYSICS 20 (2018) ARTN 023013

D Stuart, A Kuhn


Cavity-induced anticorrelated photon-emission rates of a single ion

Physical Review A American Physical Society (APS) 96 (2017) 023824

H Takahashi, E Kassa, C Christoforou, M Keller


Interference of two pulse-like spatial beams with arbitrary transverse separation

Journal of Optics IOP Publishing 18 (2016) 125201-125201

J Flórez, J-R Álvarez, O Calderón-Losada, LJ Salazar-Serrano, A Valencia


Quantum Logic with Cavity Photons From Single Atoms

PHYSICAL REVIEW LETTERS 117 (2016) ARTN 023602

A Holleczek, O Barter, A Rubenok, J Dilley, PBR Nisbet-Jones, G Langfahl-Klabes, GD Marshall, C Sparrow, JL O'Brien, K Poulios, A Kuhn, JCF Matthews


Cavity Induced Interfacing of Atoms and Light

in Engineering the Atom-Photon Interaction: Controlling Fundamental Processes with Photons, Atoms and Solids, Springer (2015) 1
Part of a series from Nano Optics and Nano Photonics

A Kuhn

This chapter introduces cavity-based light-matter quantum interfaces, with a single atom or ion in strong coupling to a high-finesse optical cavity. We discuss the deterministic generation of indistinguishable single photons from these systems; the atom-photon entanglement intractably linked to this process; and the information encoding using spatio-temporal modes within these photons. Furthermore, we show how to establish a time-reversal of the aforementioned emission process to use a coupled atom-cavity system as a quantum memory. Along the line, we also discuss the performance and characterisation of cavity photons in elementary linear-optics arrangements with single beam splitters for quantum-homodyne measurements.


Light interference In position and momentum variables: The spatial Alford and Gold effect

Proceedings of Frontiers in Optics 2015, FIO 2015 (2015)

J Flórez, O Calderó-Losada, LJ Salazar-Serrano, JR Álvarez-Velásquez, A Valencia

© 2015 Optical Society of America. Intensity modulation of two parallel-propagating beams is observed in the Fourier plane when the beams' separation is such that they do not interfere in position. This is analogous to the temporal Alford and Gold effect.


Qubits, qutrits, and ququads stored in single photons from an atom-cavity system

ADVANCES IN PHOTONICS OF QUANTUM COMPUTING, MEMORY, AND COMMUNICATION VIII 9377 (2015) ARTN 937709

A Holleczek, O Barter, G Langfahl-Klabes, A Kuhn


Cavity Induced Interfacing of Atoms and Light

Springer International Publishing (2015) 3-38

A Kuhn


Novel laser machining of optical fibers for long cavities with low birefringence

Optics Express The Optical Society 22 (2014) 31317-31317

H Takahashi, J Morphew, F Oručević, A Noguchi, E Kassa, M Keller


Single Emitters in Isolated Quantum Systems

in Single-Photon Generation and Detection, Elsevier 45 (2013) 467-539
Part of a series from Experimental Methods in the Physical Sciences

GS Solomon, C Santori, A Kuhn


Photonic qubits, qutrits and ququads accurately prepared and delivered on demand

NEW JOURNAL OF PHYSICS 15 (2013) ARTN 053007

PBR Nisbet-Jones, J Dilley, A Holleczek, O Barter, A Kuhn


Control and manipulation of cold atoms in optical tweezers

NEW JOURNAL OF PHYSICS 14 (2012) ARTN 073051

C Muldoon, L Brandt, J Dong, D Stuart, E Brainis, M Himsworth, A Kuhn


Single-photon absorption in coupled atom-cavity systems

PHYSICAL REVIEW A 85 (2012) ARTN 023834

J Dilley, P Nisbet-Jones, BW Shore, A Kuhn

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