31 research outputs found
Modified Split Ring Resonators for Efficient and Homogeneous Microwave Control of Large Volume Spin Ensembles
Quantum sensing using local defects in solid-state systems has gained
significant attention over the past several years, with impressive results
demonstrated both in Academia and in Industry. Specifically, employing large
volume and high density ensembles for beyond state-of-the-art sensitives is of
clear interest. A major obstacle for achieving such record sensitivities is
associated with the need to realize strong, homogeneous driving of the sensor
defects. Here we focus on high-frequency microwave sensing using
nitrogen-vacancy centers in diamond, and develop a modified split-ring
resonator design to address this issue. We demonstrate enhanced drive strengths
and homogeneities over large volumes compared to previous results, with
prospects for enabling the desired sensitivities. We reach Rabi frequencies of
up to 18 [MHz] with an efficiency ratio of 2 [], along with
an inhomogeneity of in a volume of
Solid-state electronic spin coherence time approaching one second
Solid-state electronic spin systems such as nitrogen-vacancy (NV) color
centers in diamond are promising for applications of quantum information,
sensing, and metrology. However, a key challenge for such solid-state systems
is to realize a spin coherence time that is much longer than the time for
quantum spin manipulation protocols. Here we demonstrate an improvement of more
than two orders of magnitude in the spin coherence time () of NV centers
compared to previous measurements: s at 77 K, which enables
coherent NV spin manipulations before decoherence. We employed
dynamical decoupling pulse sequences to suppress NV spin decoherence due to
magnetic noise, and found that is limited to approximately half of the
longitudinal spin relaxation time () over a wide range of temperatures,
which we attribute to phonon-induced decoherence. Our results apply to
ensembles of NV spins and do not depend on the optimal choice of a specific NV,
which could advance quantum sensing, enable squeezing and many-body
entanglement in solid-state spin ensembles, and open a path to simulating a
wide range of driven, interaction-dominated quantum many-body Hamiltonians
Signatures of Strong Momentum Localization via Translational-Internal Entanglement
We show that atoms or molecules subject to fields that couple their internal
and translational (momentum) states may undergo a crossover from randomization
(diffusion) to strong localization (sharpening) of their momentum distribution.
The predicted crossover should be manifest by a drastic change of the
interference pattern as a function of the coupling fields.Comment: 4 pages, 3 figure