Tin-Vacancy Quantum Emitters in Diamond

Abstract

Tin-vacancy (SnV) color centers were created in diamond by ion implantation and subsequent high temperature annealing up to 2100 °C at 7.7 GPa. The first-principles calculation suggests that the large atom of tin can be incorporated into the diamond lattice with a split-vacancy configuration, in which a tin atom sits on an interstitial site with two neighboring vacancies. The SnV center shows a sharp zero phonon line at 619 nm at room temperature. This line splits into four peaks at cryogenic temperatures with a larger ground state splitting of ~850 GHz than those of color centers based on other IV group elements, silicon-vacancy (SiV) and germanium vacancy (GeV) centers. The excited state lifetime was estimated to be ~5 ns by Hanbury Brown-Twiss interferometry measurements on single SnV quantum emitters. The order of the experimentally obtained optical transition energies comparing with the SiV and GeV centers is good agreement with the theoretical calculations.Point defect-related color centers in solid state materials are a promising approach for quantum information processing [1,2]. Nitrogen-vacancy (NV) centers in diamond have been most intensively studied from the viewpoint of both fundamental and applied sciences [3,4]. However, the zero phonon line (ZPL) of the NV center possesses a fraction of only 4 % in its total fluorescence due to its large phonon sideband (PSB). Also, the NV center suffers from external noise, leading to instability of the optical transition energy. To overcome these drawbacks, color centers based on IV group elements, silicon-vacancy (SiV) [5][6][7] and germanium-vacancy (GeV) [8][9][10][11] centers, has attracted attention owing to their large ZPL, structural symmetry robust against the external noise, and availability of quantum emission by single centers. Recently, spin control and evaluation of spin coherence time have been investigated for this two color centers [12][13][14][15][16], revealing that their spin coherence times were limited to sub-microseconds even at cryogenic temperatures < 5 K, much shorter than that of the NV center [17,18]. This limitation originates from phonon-mediated transitions between the lower and upper branches in the ground state [13][14][15][16]. Further cooling down to the sub-Kelvin regime or strain engineering is considered as a solution [15,16]. Another possibility is creation of a novel color center possessing a larger energy splitting in the ground state.For this purpose, in this study, we investigated the utilization of a IV group atom of tin (Sn, Fig. 1a).The incorporation of such a heavy atom into the diamond lattice as a form of a color center, especially single quantum emitter, has not been demonstrated yet. Here, we fabricated tin-vacancy (SnV) centers in diamond in both ensemble and single states by combination of ion implantation and subsequent high temperature annealing up to 2100 °C under a high pressure of 7.7 GPa. Low temperature optical measurements revealed that the ground state splitting of the SnV center was much larg...

Building Blocks for Quantum Network Based on Group‐IV Split‐Vacancy Centers in Diamond

“…The strong spin–orbit (SO) coupling and dynamical Jahn–Teller (DJT) interaction lift the orbital degeneracy of these states, leading to a pair of split ground and excited states, each with double spin degeneracy, as shown in Figure b. At cryogenic temperature and zero magnetic field, the transition between these energy levels lead to a characteristic four‐line emission pattern in ZPL spectrum of SiV − , GeV − , SnV − , and PbV − centers, as shown in Figure c. These optically allowed transitions form a double‐Λ system, which has been utilized to realize orbital‐based coherent control schemes .…”

Optical properties of silicon-vacancy color centers in diamond created by ion implantation and post-annealing

“…recent years on vacancy_related defects, mainly formed by an interstitial guest splitting two site vacancies along the 111 direction, like HeV 11 , SV 12 , GeV 13,14 , SnV 15 and XeV 16 centers. In this regard, silicon-vacancy (SiV) color centers have recently shown the largest brightness for singlephoton emission at room temperature 17 with a fluorescence emission concentrated in the zerophonon line (ZPL) at 738 nm 18 , with a room-temperature linewidth down to 0.7 nm 17 .…”

Diamond as a Platform for Integrated Quantum Photonics

“…Other defects which received recent attention are the tin vacancy (SnV) color center (emission wavelength ≃620 nm), the neutral SiV 0 center (emission wavelength ≃950 nm), and Pb‐related color centers (emission wavelength ≃520–560 nm) . Particular interest in these defects stems from the fact that they are expected to possess all the favorable optical properties of negative SiV and GeV centers because of the equivalent inversion symmetry of their electronic structures but much longer spin coherence times (with an electronic spin coherence time ≃1 ms already measured for the SiV° center), making them attractive candidates for the realization of long‐distance quantum networks.…”