Highlights from the Asia Pacific Region

2013 ◽  
Vol 02 (02) ◽  
pp. 29-46
Author(s):  
APPN Editorial Office
Keyword(s):  
Information Technologies ◽  
Room Temperature ◽  
Spatial Separation ◽  
Coherence Time ◽  
Nitrogen Vacancy ◽  
Asia Pacific ◽  
Ambient Conditions ◽  
Asia Pacific Region ◽  
Quantum Bits ◽  
Traditional Approaches

Quantum information technologies hold the promise of greatly outperforming traditional approaches in, e.g., cryptography, metrology and simulation. However, the ultimate goal of realizing scalable quantum computing has so far remained elusive, largely owing to the formidable difficulty in "wiring up" suitable quantum bits (qubits). In recent years, individual nitrogen-vacancy (NV-) defects in diamond have emerged as one of the most promising candidates for a solidstate qubit for two reasons. First, they possess the longest observed room-temperature coherence time of an electron spin (the qubit) to date; second, their spin can be initialized and measured with a nanoscale resolution using optical techniques under ambient conditions. However, interconnecting different NV- centres remains a big challenge. This problem is further exacerbated by the need for a large spatial separation between adjacent qubits, required for individual qubit addressability.

scholarly journals Quantum metrology with single spins in diamond under ambient conditions

2017 ◽  
Vol 5 (3) ◽  
pp. 346-355 ◽  
Author(s):  
Ming Chen ◽  
Chao Meng ◽  
Qi Zhang ◽  
Changkui Duan ◽  
Fazhan Shi ◽  
...  
Keyword(s):  
Electric Fields ◽  
Environmental Changes ◽  
Coherence Time ◽  
Quantum Systems ◽  
Nitrogen Vacancy ◽  
Quantum Metrology ◽  
Ambient Conditions ◽  
Quantum Bits ◽  
Temperature Strain ◽  
Physical Quantities

Abstract The detection of single quantum systems can reveal information that would be averaged out in traditional techniques based on ensemble measurements. The nitrogen-vacancy (NV) centers in diamond have shown brilliant prospects of performance as quantum bits and atomic sensors under ambient conditions, such as ultra-long coherence time, high fidelity control and readout of the spin state. In particular, the sensitivity of the NV center spin levels to external environmental changes makes it a versatile detector capable of measuring various physical quantities, such as temperature, strain, electric fields and magnetic fields. In this paper, we review recent progress in NV-based quantum metrology, and speculate on its future.

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.

Teleportation of a controlled-NOT gate for photon and electron-spin qubits assisted by the nitrogen-vacancy center

2015 ◽  
Vol 15 (15&16) ◽  
pp. 1397-1419
Author(s):  
Ming-Xing Luo ◽  
Hui-Ran Li
Keyword(s):  
Electron Spin ◽  
Spin System ◽  
Room Temperature ◽  
Coherence Time ◽  
Nitrogen Vacancy ◽  
Cnot Gate ◽  
Long Distance ◽  
Two Photon ◽  
Nitrogen Vacancy Center ◽  
Vacancy Center

Teleportations of quantum gates are very important in the construction of quantum network and teleportation-based model of quantum computation. Assisted with nitrogenvacancy centers, we propose several schemes to teleport the quantum CNOT gate. Deterministic CNOT gate may be implemented on a remote two-photon system, remote two electron-spin system, hybrid photon-spin system or hybrid spin-photon system. Each photon only interacts with one spin each time. Moreover, quantum channel may be constructed by all combinations of the photon or electron-spin entanglement, or their hybrid entanglement. Since these electron-spin systems have experimentally shown a long coherence time even at the room temperature, our schemes provide useful ways for long-distance quantum applications.

scholarly journals Bright Single-Photon Emitting Diodes Based on the Silicon-Vacancy Center in AlN/Diamond Heterostructures

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 361 ◽  
Author(s):  
Igor A. Khramtsov ◽  
Dmitry Yu. Fedyanin
Keyword(s):  
Quantum Information ◽  
Information Technologies ◽  
Room Temperature ◽  
Single Photon ◽  
Forward Bias ◽  
Color Centers ◽  
Practical Implementation ◽  
Ambient Conditions ◽  
Silicon Vacancy ◽  
Photon Sources

Practical implementation of many quantum information and sensing technologies relies on the ability to efficiently generate and manipulate single-photon photons under ambient conditions. Color centers in diamond, such as the silicon-vacancy (SiV) center, have recently emerged as extremely attractive single-photon emitters for room temperature applications. However, diamond is a material at the interface between insulators and semiconductors. Therefore, it is extremely difficult to excite color centers electrically and consequently develop bright and efficient electrically driven single-photon sources. Here, using a comprehensive theoretical approach, we propose and numerically demonstrate a concept of a single-photon emitting diode (SPED) based on a SiV center in a nanoscale AlN/diamond heterojunction device. We find that in spite of the high potential barrier for electrons in AlN at the AlN/diamond heterojunction, under forward bias, electrons can be efficiently injected from AlN into the i-type diamond region of the n-AlN/i-diamond/p-diamond heterostructure, which ensures bright single-photon electroluminescence (SPEL) of the SiV center located in the i-type diamond region. The maximum SPEL rate is more than five times higher than what can be achieved in SPEDs based on diamond p-i-n diodes. Despite the high density of defects at the AlN/diamond interface, the SPEL rate can reach about 4 Mcps, which coincides with the limit imposed by the quantum efficiency and the lifetime of the shelving state of the SiV center. These findings provide new insights into the development of bright room-temperature electrically driven single-photon sources for quantum information technologies and, we believe, stimulate further research in this area.

scholarly journals Ultra-sensitive hybrid diamond nanothermometer

2020 ◽  
Author(s):  
Chu-Feng Liu ◽  
Weng-Hang Leong ◽  
Kangwei Xia ◽  
Xi Feng ◽  
Amit Finkler ◽  
...  
Keyword(s):  
Temperature Sensitivity ◽  
Magnetic Nanoparticle ◽  
Coherence Time ◽  
Nitrogen Vacancy ◽  
Field Variation ◽  
Ambient Conditions ◽  
Nanoscale Systems ◽  
Copper Nickel Alloy ◽  
Improved Design ◽  
Spin Resonances

Abstract Nitrogen-vacancy (NV) centers in diamond are promising quantum sensors for their long spin coherence time under ambient conditions. However, their spin resonances are relatively insensitive to non-magnetic parameters such as temperature. A magnetic-nanoparticle-nanodiamond hybrid thermometer, where the temperature change is converted to the magnetic field variation near the Curie temperature, was demonstrated to have enhanced temperature sensitivity ($11{\rm{\;mK\;H}}{{\rm{z}}^{ - 1/2}}$)  [Phys. Rev. X 8, 011042 (2018)], but the sensitivity was limited by the large spectral broadening of ensemble spins in nanodiamonds. To overcome this limitation, here we show an improved design of a hybrid nanothermometer using a single NV center in a diamond nanopillar coupled with a single magnetic nanoparticle of copper-nickel alloy, and demonstrate a temperature sensitivity of $76{\rm{\;\mu K\;H}}{{\rm{z}}^{ - 1/2}}$. This hybrid design enables detection of 2 millikelvin temperature changes with temporal resolution of 5 milliseconds. The ultra-sensitive nanothermometer offers a new tool to investigate thermal processes in nanoscale systems.

Review of Counseling in the Asia-Pacific Region.

1995 ◽  
Vol 40 (4) ◽  
pp. 383-384
Author(s):  
Terri Gullickson
Keyword(s):  
Asia Pacific ◽  
Pacific Region ◽  
Asia Pacific Region
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