17 research outputs found
Stark Tuning and Electrical Charge State Control of Single Divacancies in Silicon Carbide
Neutrally charged divacancies in silicon carbide (SiC) are paramagnetic color
centers whose long coherence times and near-telecom operating wavelengths make
them promising for scalable quantum communication technologies compatible with
existing fiber optic networks. However, local strain inhomogeneity can randomly
perturb their optical transition frequencies, which degrades the
indistinguishability of photons emitted from separate defects, and hinders
their coupling to optical cavities. Here we show that electric fields can be
used to tune the optical transition frequencies of single neutral divacancy
defects in 4H-SiC over a range of several GHz via the DC Stark effect. The same
technique can also control the charge state of the defect on microsecond
timescales, which we use to stabilize unstable or non-neutral divacancies into
their neutral charge state. Using fluorescence-based charge state detection, we
show both 975 nm and 1130 nm excitation can prepare its neutral charge state
with near unity efficiency.Comment: 12 pages, 4 figure
Isolated spin qubits in SiC with a high-fidelity infrared spin-to-photon interface
The divacancies in SiC are a family of paramagnetic defects that show promise
for quantum communication technologies due to their long-lived electron spin
coherence and their optical addressability at near-telecom wavelengths.
Nonetheless, a mechanism for high-fidelity spin-to-photon conversion, which is
a crucial prerequisite for such technologies, has not yet been demonstrated.
Here we demonstrate a high-fidelity spin-to-photon interface in isolated
divacancies in epitaxial films of 3C-SiC and 4H-SiC. Our data show that
divacancies in 4H-SiC have minimal undesirable spin-mixing, and that the
optical linewidths in our current sample are already similar to those of recent
remote entanglement demonstrations in other systems. Moreover, we find that
3C-SiC divacancies have millisecond Hahn-echo spin coherence time, which is
among the longest measured in a naturally isotopic solid. The presence of
defects with these properties in a commercial semiconductor that can be
heteroepitaxially grown as a thin film on shows promise for future quantum
networks based on SiC defects.Comment: 26 pages, 4 figure
Stark Tuning and Electrical Charge State Control of Single Divacancies in Silicon Carbide
Neutrally charged divacancies in silicon carbide (SiC) which are known as paramagnetic color centers, their long coherence times and near-telecom operating wavelengths. However, local strain inhomogeneity can randomly perturb their optical transition frequencies, which degrades the indistinguishability of photons emitted from separate defects and hinders their coupling to optical cavities. In this study, electric fields can be used to tune the optical transition frequencies of single neutral divacancy defects in 4H-SiC over a range of several GHz via the DC Stark effect. The same technique can also control the charge state of the defect on microsecond timescales. Using fluorescence-based charge state detection, it is demonstrated that both 975 and 1130 nm excitation can prepare their neutral charge state with near unity efficiency
Engineered Micro- and Nanoscale Diamonds as Mobile Probes for High-Resolution Sensing in Fluid
The nitrogen-vacancy (NV) center
in diamond is an attractive platform
for quantum information and sensing applications because of its room
temperature operation and optical addressability. A major research
effort focuses on improving the quantum coherence of this defect in
engineered micro- and nanoscale diamond particles (DPs), which could
prove useful for high-resolution sensing in fluidic environments.
In this work we fabricate cylindrical diamonds particles with finely
tuned and highly reproducible sizes (diameter and height ranging from
100 to 700 and 500 nm to 2 μm, respectively) using high-purity,
single-crystal diamond membranes with shallow-doped NV centers. We
show that the spin coherence time of the NV centers in these particles
exceeds 700 μs, opening the possibility for the creation of
ultrahigh sensitivity micro- and nanoscale sensors. Moreover, these
particles can be efficiently transferred into a water suspension and
delivered to the region to probe. In particular, we introduce a DP
suspension inside a microfluidic circuit and control position and
orientation of the particles using an optical trapping apparatus.
We demonstrate a DC magnetic sensitivity of 9 μT/√Hz
in fluid as well as long-term trapping stability (>30 h), which
paves
the way toward the use of high-sensitivity pulse techniques on contactless
probes manipulated within biological settings
Isolated Spin Qubits in SiC with a High-Fidelity Infrared Spin-to-Photon Interface
The divacancies in Silicon Carbide are a family of paramagnetic defects that show promise for quantum technologies due to their long-lived electron spin coherence and their optical addressability at near-telecom wavelengths. Nonetheless, a high-fidelity spin-photon interface, which is a crucial prerequisite for such technologies, has not yet been demonstrated. It is demonstrated that such an interface exists in isolated divacancies in epitaxial films of 3C-SiC and 4H-SiC. Our data show that divacancies in 4H-SiC have minimal undesirable spin mixing, and that the optical linewidths in our current sample are already almost the same as those of recent remote entanglement demonstrations in other systems. Moreover, we find that 3C-SiC divacancies have a millisecond Hahn-echo spin coherence time
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Isolated spin qubits in SiC with a high-fidelity infrared spin-to-photon interface
The divacancies in SiC are a family of paramagnetic defects that show promise for quantum communication technologies due to their long-lived electron spin coherence and their optical addressability at near-telecom wavelengths. Nonetheless, a high-fidelity spin-photon interface, which is a crucial prerequisite for such technologies, has not yet been demonstrated. Here, we demonstrate that such an interface exists in isolated divacancies in epitaxial films of 3C-SiC and 4H-SiC. Our data show that divacancies in 4H-SiC have minimal undesirable spin mixing, and that the optical linewidths in our current sample are already similar to those of recent remote entanglement demonstrations in other systems. Moreover, we find that 3C-SiC divacancies have a millisecond Hahn-echo spin coherence time, which is among the longest measured in a naturally isotopic solid. The presence of defects with these properties in a commercial semiconductor that can be heteroepitaxially grown as a thin film on Si shows promise for future quantum networks based on SiC defects