scholarly journals Quantum control in spintronics

2011 ◽  
Vol 369 (1948) ◽  
pp. 3229-3248 ◽  
Author(s):  
A. Ardavan ◽  
G. A. D. Briggs
Keyword(s):  
Quantum Control ◽  
Quantum Information Processing ◽  
Nitrogen Vacancy ◽  
Triplet States ◽  
Spin States ◽  
Electron Spins ◽  
Nuclear Spins ◽  
Holographic Storage ◽  
New Era ◽  
Quantum Phenomena

Superposition and entanglement are uniquely quantum phenomena. Superposition incorporates a phase that contains information surpassing any classical mixture. Entanglement offers correlations between measurements in quantum systems that are stronger than any that would be possible classically. These give quantum computing its spectacular potential, but the implications extend far beyond quantum information processing. Early applications may be found in entanglement-enhanced sensing and metrology. Quantum spins in condensed matter offer promising candidates for investigating and exploiting superposition and entanglement, and enormous progress is being made in quantum control of such systems. In gallium arsenide (GaAs), individual electron spins can be manipulated and measured, and singlet–triplet states can be controlled in double-dot structures. In silicon, individual electron spins can be detected by ionization of phosphorus donors, and information can be transferred from electron spins to nuclear spins to provide long memory times. Electron and nuclear spins can be manipulated in nitrogen atoms incarcerated in fullerene molecules, which in turn can be assembled in ordered arrays. Spin states of charged nitrogen vacancy centres in diamond can be manipulated and read optically. Collective spin states in a range of materials systems offer scope for holographic storage of information. Conditions are now excellent for implementing superposition and entanglement in spintronic devices, thereby opening up a new era of quantum technologies.

Towards quantum networks of single spins: analysis of a quantum memory with an optical interface in diamond

2015 ◽  
Vol 184 ◽  
pp. 173-182 ◽  
Author(s):  
M. S. Blok ◽  
N. Kalb ◽  
A. Reiserer ◽  
T. H. Taminiau ◽  
R. Hanson
Keyword(s):  
Quantum Information Processing ◽  
Quantum States ◽  
Nitrogen Vacancy ◽  
Nuclear Spins ◽  
Quantum Repeater ◽  
Quantum Networks ◽  
Entanglement Generation ◽  
Quantum Bit ◽  
Single Defect ◽  
Coupling Parameters

Single defect centers in diamond have emerged as a powerful platform for quantum optics experiments and quantum information processing tasks. Connecting spatially separated nodes via optical photons into a quantum network will enable distributed quantum computing and long-range quantum communication. Initial experiments on trapped atoms and ions as well as defects in diamond have demonstrated entanglement between two nodes over several meters. To realize multi-node networks, additional quantum bit systems that store quantum states while new entanglement links are established are highly desirable. Such memories allow for entanglement distillation, purification and quantum repeater protocols that extend the size, speed and distance of the network. However, to be effective, the memory must be robust against the entanglement generation protocol, which typically must be repeated many times. Here we evaluate the prospects of using carbon nuclear spins in diamond as quantum memories that are compatible with quantum networks based on single nitrogen vacancy (NV) defects in diamond. We present a theoretical framework to describe the dephasing of the nuclear spins under repeated generation of NV spin-photon entanglement and show that quantum states can be stored during hundreds of repetitions using typical experimental coupling parameters. This result demonstrates that nuclear spins with weak hyperfine couplings are promising quantum memories for quantum networks.

Quantum-entanglement storage and extraction in quantum network node

2018 ◽  
Vol 16 (01) ◽  
pp. 1850009 ◽  
Author(s):  
ZhuoYu Shan ◽  
Yong Zhang
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Entanglement ◽  
Information Technologies ◽  
Quantum Information Processing ◽  
Bell State ◽  
Nitrogen Vacancy ◽  
Quantum Network ◽  
Nuclear Spins ◽  
Nv Centers

Quantum computing and quantum communication have become the most popular research topic. Nitrogen-vacancy (NV) centers in diamond have been shown the great advantage of implementing quantum information processing. The generation of entanglement between NV centers represents a fundamental prerequisite for all quantum information technologies. In this paper, we propose a scheme to realize the high-fidelity storage and extraction of quantum entanglement information based on the NV centers at room temperature. We store the entangled information of a pair of entangled photons in the Bell state into the nuclear spins of two NV centers, which can make these two NV centers entangled. And then we illuminate how to extract the entangled information from NV centers to prepare on-demand entangled states for optical quantum information processing. The strategy of engineering entanglement demonstrated here maybe pave the way towards a NV center-based quantum network.

scholarly journals Algorithmic decomposition for efficient multiple nuclear spin detection in diamond

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hyunseok Oh ◽  
Jiwon Yun ◽  
M. H. Abobeih ◽  
Kyung-Hoon Jung ◽  
Kiho Kim ◽  
...  
Keyword(s):  
Hyperfine Interaction ◽  
Nuclear Spin ◽  
Systematic Approach ◽  
Quantum Information Processing ◽  
Nitrogen Vacancy ◽  
Nuclear Spectroscopy ◽  
Nuclear Spins ◽  
Systematic Analysis ◽  
And Control ◽  
Spin Detection

Abstract 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.

scholarly journals Deep learning enhanced individual nuclear-spin detection

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Kyunghoon Jung ◽  
M. H. Abobeih ◽  
Jiwon Yun ◽  
Gyeonghun Kim ◽  
Hyunseok Oh ◽  
...  
Keyword(s):  
Deep Learning ◽  
Nuclear Spin ◽  
Quantum Information Processing ◽  
Nuclear Interaction ◽  
Spin Systems ◽  
Nitrogen Vacancy ◽  
Atomic Scale ◽  
Automatic Identification ◽  
Nuclear Spins ◽  
Wide Range

AbstractThe detection of nuclear spins using individual electron spins has enabled diverse opportunities in quantum sensing and quantum information processing. Proof-of-principle experiments have demonstrated atomic-scale imaging of nuclear-spin samples and controlled multi-qubit registers. However, to image more complex samples and to realize larger-scale quantum processors, computerized methods that efficiently and automatically characterize spin systems are required. Here, we realize a deep learning model for automatic identification of nuclear spins using the electron spin of single nitrogen-vacancy (NV) centers in diamond as a sensor. Based on neural network algorithms, we develop noise recovery procedures and training sequences for highly non-linear spectra. We apply these methods to experimentally demonstrate the fast identification of 31 nuclear spins around a single NV center and accurately determine the hyperfine parameters. Our methods can be extended to larger spin systems and are applicable to a wide range of electron-nuclear interaction strengths. These results pave the way towards efficient imaging of complex spin samples and automatic characterization of large spin-qubit registers.

Quantum Polaritonic

2017 ◽  
Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy
Keyword(s):  
Phase Transitions ◽  
Quantum Information ◽  
Quantum Information Processing ◽  
Quantum Phase Transitions ◽  
Macroscopic Quantum ◽  
Quantum Simulations ◽  
Macroscopic Quantum Phenomena ◽  
Microcavity Polaritons ◽  
Quantum Phenomena ◽  
The One

Microcavity polaritons have demonstrated their unique propensity to host macroscopic quantum phenomena. While they appear to be highly promising for applications in a classical realm, they are still far from competing even with decade old electronics. Another playground where polaritons could emerge as strong contenders is the microscopic quantum regime with single-particle effects and nonlinearities at the one-polariton level. Several theoretical proposals exist to explore polariton blockade mechanisms, realize sophisticated quantum phase transitions, implement quantum simulations and/or quantum information processing, thereby opening a new page of the polariton physics when such ideas will be implemented in the laboratory.

scholarly journals Optical spin-state polarization in a binuclear europium complex towards molecule-based coherent light-spin interfaces

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kuppusamy Senthil Kumar ◽  
Diana Serrano ◽  
Aline M. Nonat ◽  
Benoît Heinrich ◽  
Lydia Karmazin ◽  
...  
Keyword(s):  
Ground State ◽  
Quantum Information Processing ◽  
Optical Transition ◽  
Molecular Engineering ◽  
Coherent Light ◽  
Nuclear Spins ◽  
Rare Earth Ion ◽  
Molecular Systems ◽  
Homogeneous Linewidth ◽  
State Spin

AbstractThe success of the emerging field of solid-state optical quantum information processing (QIP) critically depends on the access to resonant optical materials. Rare-earth ion (REI)-based molecular systems, whose quantum properties could be tuned taking advantage of molecular engineering strategies, are one of the systems actively pursued for the implementation of QIP schemes. Herein, we demonstrate the efficient polarization of ground-state nuclear spins—a fundamental requirement for all-optical spin initialization and addressing—in a binuclear Eu(III) complex, featuring inhomogeneously broadened 5D0 → 7F0 optical transition. At 1.4 K, long-lived spectral holes have been burnt in the transition: homogeneous linewidth (Γh) = 22 ± 1 MHz, which translates as optical coherence lifetime (T2opt) = 14.5 ± 0.7 ns, and ground-state spin population lifetime (T1spin) = 1.6 ± 0.4 s have been obtained. The results presented in this study could be a progressive step towards the realization of molecule-based coherent light-spin QIP interfaces.

scholarly journals Room-temperature control and electrical readout of individual nitrogen-vacancy nuclear spins

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michal Gulka ◽  
Daniel Wirtitsch ◽  
Viktor Ivády ◽  
Jelle Vodnik ◽  
Jaroslav Hruby ◽  
...  
Keyword(s):  
Dipolar Interaction ◽  
Coherence Time ◽  
Wide Bandgap ◽  
Nitrogen Vacancy ◽  
Ambient Conditions ◽  
Nuclear Spins ◽  
Quantum Device ◽  
Nanoscale Electronics ◽  
Quantum Processor ◽  
Processor Unit

AbstractNuclear spins in semiconductors are leading candidates for future quantum technologies, including quantum computation, communication, and sensing. Nuclear spins in diamond are particularly attractive due to their long coherence time. With the nitrogen-vacancy (NV) centre, such nuclear qubits benefit from an auxiliary electronic qubit, which, at cryogenic temperatures, enables probabilistic entanglement mediated optically by photonic links. Here, we demonstrate a concept of a microelectronic quantum device at ambient conditions using diamond as wide bandgap semiconductor. The basic quantum processor unit – a single 14N nuclear spin coupled to the NV electron – is read photoelectrically and thus operates in a manner compatible with nanoscale electronics. The underlying theory provides the key ingredients for photoelectric quantum gate operations and readout of nuclear qubit registers. This demonstration is, therefore, a step towards diamond quantum devices with a readout area limited by inter-electrode distance rather than by the diffraction limit. Such scalability could enable the development of electronic quantum processors based on the dipolar interaction of spin-qubits placed at nanoscopic proximity.

scholarly journals Intersystem crossing rates of single perylene molecules in ortho-dichlorobenzene

2016 ◽  
Vol 18 (26) ◽  
pp. 17655-17659 ◽  
Author(s):  
Nico R. Verhart ◽  
Pedro Navarro ◽  
Sanli Faez ◽  
Michel Orrit
Keyword(s):  
Optical Switching ◽  
Intersystem Crossing ◽  
Triplet States ◽  
Spin States ◽  
Molecular Fluorescence

Triplet states can be interesting for optical switching of molecular fluorescence as well as quantum experiments relying on the manipulation of spin states.

THE TRAPPED-ION QUBIT: COHERENT CONTROL IN INFINITE-DIMENSIONAL QUANTUM SYSTEMS

2009 ◽  
Vol 24 (32) ◽  
pp. 2565-2578
Author(s):  
C. RANGAN
Keyword(s):  
Quantum Computing ◽  
Quantum System ◽  
Quantum Control ◽  
Coherent Control ◽  
Quantum Information Processing ◽  
Quantum Systems ◽  
Infinite Dimensional ◽  
Trapped Ion ◽  
Rich Variety ◽  
Control Research

Theories of quantum control have, until recently, made the assumption that the Hilbert space of a quantum system can be truncated to finite dimensions. Such truncations, which can be achieved for most quantum systems via bandwidth restrictions, have enabled the development of a rich variety of quantum control and optimal control schemes. Recent studies in quantum information processing have addressed the control of infinite-dimensional quantum systems such as the quantum states of a trapped-ion. Controllability in an infinite-dimensional quantum system is hard to prove with conventional methods, and infinite-dimensional systems provide unique challenges in designing control fields. In this paper, we will discuss the control of a popular system for quantum computing the trapped-ion qubit. This system, modeled by a spin-half particle coupled to a quantized harmonic oscillator, is an example for a surprisingly rich variety of control problems. We will show how this infinite-dimensional quantum system can be examined via the lens of the Finite Controllability Theorem, two-color STIRAP, the generalized Heisenberg system, etc. These results are important from the viewpoint of developing more efficient quantum control protocols, particularly in quantum computing systems. This work shows how one can expand the scope of quantum control research to beyond that of finite-dimensional quantum systems.

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