240 research outputs found
Adiabatic Dynamical-Decoupling Based Control of Nuclear Spin Registers
The use of the nuclear spins surrounding electron spin qubits as quantum
registers and long-lived memories opens the way to new applications in quantum
information and biological sensing. Hence, there is a need for generic and
robust forms of control of the nuclear registers. Although adiabatic gates are
widely used in quantum information, they can become too slow to outpace
decoherence. Here, we introduce a technique whereby adiabatic gates arise from
the dynamical decoupling protocols that simultaneously extend coherence. We
illustrate this pulse-based adiabatic control for nuclear spins around NV
centers in diamond. We obtain a closed-form expression from Landau-Zener theory
and show that it reliably describes the dynamics. By identifying robust Floquet
states, we show that the technique enables polarisation, one-shot flips and
state storage for nuclear spins. These results introduce a new control paradigm
that combines dynamical decoupling with adiabatic evolution.Comment: 5 page
Detection and control of individual nuclear spins using a weakly coupled electron spin
We experimentally isolate, characterize and coherently control up to six
individual nuclear spins that are weakly coupled to an electron spin in
diamond. Our method employs multi-pulse sequences on the electron spin that
resonantly amplify the interaction with a selected nuclear spin and at the same
time dynamically suppress decoherence caused by the rest of the spin bath. We
are able to address nuclear spins with interaction strengths that are an order
of magnitude smaller than the electron spin dephasing rate. Our results provide
a route towards tomography with single-nuclear-spin sensitivity and greatly
extend the number of available quantum bits for quantum information processing
in diamond
Sensing distant nuclear spins with a single electron spin
We experimentally demonstrate the use of a single electronic spin to measure
the quantum dynamics of distant individual nuclear spins from within a
surrounding spin bath. Our technique exploits coherent control of the electron
spin, allowing us to isolate and monitor nuclear spins weakly coupled to the
electron spin. Specifically, we detect the evolution of distant individual
carbon-13 nuclear spins coupled to single nitrogen vacancy centers in a diamond
lattice with hyperfine couplings down to a factor of 8 below the electronic
spin bare dephasing rate. Potential applications to nanoscale magnetic
resonance imaging and quantum information processing are discussed.Comment: Corrected typos, updated references. 5 pages, 4 figures, and
supplemental materia
Algorithmic decomposition for efficient multiple nuclear spin detection in diamond
Efficiently detecting and characterizing individual spins in solid-state
hosts is an essential step to expand the fields of quantum sensing and quantum
information processing. While selective detection and control of a few 13C
nuclear spins in diamond have been demonstrated using the electron spin of
nitrogen-vacancy (NV) centers, a reliable, efficient, and automatic
characterization method is desired. Here, we develop an automated algorithmic
method for decomposing spectral data to identify and characterize multiple
nuclear spins in diamond. We demonstrate efficient nuclear spin identification
and accurate reproduction of hyperfine interaction components for both virtual
and experimental nuclear spectroscopy data. We conduct a systematic analysis of
this methodology and discuss the range of hyperfine interaction components of
each nuclear spin that the method can efficiently detect. The result
demonstrates a systematic approach that automatically detects nuclear spins
with the aid of computational methods, facilitating the future scalability of
devices.Comment: 4 figures, 2 table
Entanglement of dark electron-nuclear spin defects in diamond
A promising approach for multi-qubit quantum registers is to use optically
addressable spins to control multiple dark electron-spin defects in the
environment. While recent experiments have observed signatures of coherent
interactions with such dark spins, it is an open challenge to realize the
individual control required for quantum information processing. Here we
demonstrate the initialisation, control and entanglement of individual dark
spins associated to multiple P1 centers, which are part of a spin bath
surrounding a nitrogen-vacancy center in diamond. We realize projective
measurements to prepare the multiple degrees of freedom of P1 centers - their
Jahn-Teller axis, nuclear spin and charge state - and exploit these to
selectively access multiple P1s in the bath. We develop control and single-shot
readout of the nuclear and electron spin, and use this to demonstrate an
entangled state of two P1 centers. These results provide a proof-of-principle
towards using dark electron-nuclear spin defects as qubits for quantum sensing,
computation and networks
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