Tunable cavity coupling of the zero phonon line of a nitrogen-vacancy defect in diamond

Abstract

We demonstrate the tunable enhancement of the zero phonon line of a single nitrogen-vacancy colour centre in diamond at cryogenic temperature. An open cavity fabricated using focused ion beam milling provides mode volumes as small as 1.24 μm 3 (4.7 3 l ) and quality factor Q 3000.  In situ tuning of the cavity resonance is achieved with piezoelectric actuators. At optimal coupling to a TEM 00 cavity mode, the signal from individual zero phonon line transitions is enhanced by a factor of 6.25 and the overall emission rate of the NV − centre is increased by 40% compared with that measured from the same centre in the absence of cavity field confinement. This result represents a step forward in the realisation of efficient spin-photon interfaces and scalable quantum computing using optically addressable solid state spin qubits.

Practical repeaters for ultralong-distance quantum communication

“…An example of this may be in NV centers where we wish to use the zero-photon line (since only these photons are perfectly entangled with the emitting center). Recent advancements have produced NV centers with Debye-Waller factors of 0.4, requiring a seven-fold increase in the number of qubits needed per station [27]. The inset of FIG.…”

First principles predictions of magneto-optical data for semiconductor point defect identification: the case of divacancy defects in 4H–SiC

“…The physics of semiconductor point defects is of outstanding importance for controlling their optical and electrical properties [1,2].The study of point defect properties is a field of much active interest due to recent discoveries of numerous magnetically and optically active defect centers that can act as a single photon source [3][4][5][6][7] or a quantum bit (qubit) [8][9][10]. So far, the most thoroughly investigated point defect for use in qubits are the NV-center in diamond [11][12][13][14][15][16], phosphor in silicon [17][18][19] and divacancy [20][21][22] in silicon carbide (SiC). Furthermore, numerous other centers in various semiconducting host materials are proposed as potential magneto-optical centers, such as silicon-vacancy and germanium-vacancy centers in diamond [23,24], silicon vacancy in SiC [25,26], carbon anti-site vacancy pair in SiC [27], Ce 3+ and Pr 3+ ions in yttrium aluminum garnet [5,28], Eu and Nd 3+ ion in yttrium orthosilicate [29,30], Nd 3+ yttrium orthovanadate [31], defect spins in aluminum nitride [32], etc.…”

Design and low-temperature characterization of a tunable microcavity for diamond-based quantum networks

“…[13][14][15][16] In recent years, the open Fabry-Perot microcavity 17 has emerged as a promising platform for diamond emitters. [18][19][20][21][22] Such a microcavity provides in-situ spatial and spectral tunability, while reaching strong field confinement due to its small mode volume V and high quality factor Q. Moreover, this architecture allows for the use of diamond slabs 23 in which the NV center can be relatively far removed from surfaces and thus exhibit bulklike optical properties, as required for quantum network applications.…”