21 research outputs found
Optical measurement of heteronuclear cross-relaxation interactions in Tm:YAG
We investigate cross-relaxation interactions between Tm and Al in Tm:YAG
using two optical methods: spectral holeburning and stimulated echoes. These
interactions lead to a reduction in the hyperfine lifetime at magnetic fields
that bring the Tm hyperfine transition into resonance with an Al transition. We
develop models for measured echo decay curves and holeburning spectra near a
resonance, which are used to show that the Tm-Al interaction has a resonance
width of 10~kHz and reduces the hyperfine lifetime to 0.5 ms. The antihole
structure is consistent with an interaction dominated by the Al nearest
neighbors at 3.0 Angstroms, with some contribution from the next nearest
neighbors at 3.6 Angstroms.Comment: 13 pages, 9 figure
Precision measurement of electronic ion-ion interactions between neighboring Eu3+ optical centers
We report measurements of discrete excitation-induced frequency shifts on the 7F0→5D0 transition of the Eu+ center in La:Lu:EuCl3·6D2O resulting from the optical excitation of neighboring Eu3+ ions. Shifts of up to 46.081±0.005 MHz were observed. The magnitude of the interaction between neighboring ions was found to be significantly larger than expected from the electric dipole-dipole mechanism often observed in rare earth systems. We show that a large network of interacting and individually addressable centers can be created by lightly doping crystals otherwise stoichiometric in the optically active rare earth ion, and that this network could be used to implement a quantum processor with more than ten qubits
Optimising the Efficiency of a Quantum Memory based on Rephased Amplified Spontaneous Emission
We studied the recall efficiency as a function of optical depth of rephased
amplified spontaneous emission (RASE), a protocol for generating entangled
light. The experiments were performed on the
transition in the rare-earth doped crystal
Pr:YSiO, using a four-level echo sequence between four
hyperfine levels to rephase the emission. Rephased emission was observed for
optical depths in the range of = 0.8 to 2.0 with a maximum rephasing
efficiency of 14 % observed while incorporating spin storage. This efficiency
is a significant improvement over the previously reported non-classical result
but is well short of the predicted efficiency. We discuss the possible
mechanisms limiting the protocol's performance, and suggest ways to overcome
these limits.Comment: 5 pages, 5 figure
Probing the tail of the nuclear potential between identical nuclei with quasi-elastic Mott scattering
Sub-megahertz homogeneous linewidth for Er in Si via in situ single photon detection
We studied the optical properties of a resonantly excited trivalent Er
ensemble in Si accessed via in situ single photon detection. A novel approach
which avoids nanofabrication on the sample is introduced, resulting in a highly
efficient detection of 70 excitation frequencies, of which 63 resonances have
not been observed in literature. The center frequencies and optical lifetimes
of all resonances have been extracted, showing that 5% of the resonances are
within 1 GHz of our electrically detected resonances and that the optical
lifetimes range from 0.5 ms up to 1.5 ms. We observed inhomogeneous broadening
of less than 400 MHz and an upper bound on the homogeneous linewidth of 1.4 MHz
and 0.75 MHz for two separate resonances, which is a reduction of more than an
order of magnitude observed to date. These narrow optical transition properties
show that Er in Si is an excellent candidate for future quantum information and
communication applications.Comment: 12 pages, 13 figure
Millisecond electron spin coherence time for erbium ions in silicon
Spins in silicon that are accessible via a telecom-compatible optical
transition are a versatile platform for quantum information processing that can
leverage the well-established silicon nanofabrication industry. Key to these
applications are long coherence times on the optical and spin transitions to
provide a robust system for interfacing photonic and spin qubits. Here, we
report telecom-compatible Er3+ sites with long optical and electron spin
coherence times, measured within a nuclear spin-free silicon crystal (<0.01%
29Si) using optical detection. We investigate two sites and find 0.1 GHz
optical inhomogeneous linewidths and homogeneous linewidths below 70 kHz for
both sites. We measure the electron spin coherence time of both sites using
optically detected magnetic resonance and observe Hahn echo decay constants of
0.8 ms and 1.2 ms at around 11 mT. These optical and spin properties of Er3+:Si
are an important milestone towards using optically accessible spins in silicon
for a broad range of quantum information processing applications.Comment: 14 pages, 6 figure