scholarly journals Coherence time of a cold-atom laser below threshold

2020 ◽  
Vol 45 (19) ◽  
pp. 5448
Author(s):  
Graeme Harvie ◽  
Adam Butcher ◽  
Jon Goldwin
Keyword(s):  
Cold Atom ◽  
Coherence Time ◽  
Atom Laser

Coherence time limit of entangled paired photons generated in a cold atom cloud

2015 ◽  
Author(s):  
J. F. Chen ◽  
Zhiguang Han ◽  
Peng Qian ◽  
L. Zhou ◽  
Weiping Zhang
Keyword(s):  
Cold Atom ◽  
Coherence Time ◽  
Time Limit ◽  
Atom Cloud

Operation of a “Cold-Atom Laser” in a Magneto-Optical Trap

1992 ◽  
Vol 18 (8) ◽  
pp. 685-688 ◽  
Author(s):  
L Hilico ◽  
C Fabre ◽  
E Giacobino
Keyword(s):  
Optical Trap ◽  
Cold Atom ◽  
Magneto Optical Trap ◽  
Atom Laser

scholarly journals Improving cold-atom sensors with quantum entanglement: Prospects and challenges

2021 ◽  
Vol 118 (14) ◽  
pp. 140501
Author(s):  
Stuart S. Szigeti ◽  
Onur Hosten ◽  
Simon A. Haine
Keyword(s):  
Quantum Entanglement ◽  
Cold Atom

scholarly journals Sensing Electrochemical Signals Using a Nitrogen-Vacancy Center in Diamond

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 358
Author(s):  
Hossein T. Dinani ◽  
Enrique Muñoz ◽  
Jeronimo R. Maze
Keyword(s):  
Electric Field ◽  
Electron Spin ◽  
Electrolyte Solution ◽  
High Sensitivity ◽  
Theoretical Work ◽  
Coherence Time ◽  
Nitrogen Vacancy ◽  
Local Concentration ◽  
Concentration Of Ions ◽  
Nv Center

Chemical sensors with high sensitivity that can be used under extreme conditions and can be miniaturized are of high interest in science and industry. The nitrogen-vacancy (NV) center in diamond is an ideal candidate as a nanosensor due to the long coherence time of its electron spin and its optical accessibility. In this theoretical work, we propose the use of an NV center to detect electrochemical signals emerging from an electrolyte solution, thus obtaining a concentration sensor. For this purpose, we propose the use of the inhomogeneous dephasing rate of the electron spin of the NV center (1/T2★) as a signal. We show that for a range of mean ionic concentrations in the bulk of the electrolyte solution, the electric field fluctuations produced by the diffusional fluctuations in the local concentration of ions result in dephasing rates that can be inferred from free induction decay measurements. Moreover, we show that for a range of concentrations, the electric field generated at the position of the NV center can be used to estimate the concentration of ions.

scholarly journals Practical Security of RSA Against NTC-Architecture Quantum Computing Attacks

2021 ◽  
Author(s):  
Kai Li ◽  
Qing-yu Cai
Keyword(s):  
Quantum Computing ◽  
Ion Trap ◽  
Quantum Algorithms ◽  
Coherence Time ◽  
Quantum Computers ◽  
Quantum Time ◽  
Speed Up ◽  
Key Length ◽  
Concurrent Architecture ◽  
Qubit Gate

AbstractQuantum algorithms can greatly speed up computation in solving some classical problems, while the computational power of quantum computers should also be restricted by laws of physics. Due to quantum time-energy uncertainty relation, there is a lower limit of the evolution time for a given quantum operation, and therefore the time complexity must be considered when the number of serial quantum operations is particularly large. When the key length is about at the level of KB (encryption and decryption can be completed in a few minutes by using standard programs), it will take at least 50-100 years for NTC (Neighbor-only, Two-qubit gate, Concurrent) architecture ion-trap quantum computers to execute Shor’s algorithm. For NTC architecture superconducting quantum computers with a code distance 27 for error-correcting, when the key length increased to 16 KB, the cracking time will also increase to 100 years that far exceeds the coherence time. This shows the robustness of the updated RSA against practical quantum computing attacks.

scholarly journals Fine structures of valley-polarized excitonic states in monolayer transitional metal dichalcogenides

Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1811-1829 ◽  
Author(s):  
Zhipeng Li ◽  
Tianmeng Wang ◽  
Shengnan Miao ◽  
Zhen Lian ◽  
Su-Fei Shi
Keyword(s):  
Optical Excitation ◽  
Coherence Time ◽  
Two Dimensions ◽  
Degree Of Freedom ◽  
Research Progress ◽  
Many Body ◽  
Transitional Metal ◽  
Metal Dichalcogenides ◽  
Fine Structures ◽  
Excitonic States

AbstractMonolayer transitional metal dichalcogenides (TMDCs), a new class of atomically thin semiconductor, respond to optical excitation strongly with robust excitons, which stem from the reduced screening in two dimensions. These excitons also possess a new quantum degree of freedom known as valley spin, which has inspired the field of valleytronics. The strongly enhanced Coulomb interaction allows the exciton to bind with other particles to form new excitonic states. However, despite the discovery of trions, most of the excitonic states in monolayer TMDCs remain elusive until recently, when new light was shed into the fascinating excitonic fine structures with drastically improved sample quality through boron nitride encapsulation. Here, we review the latest research progress on fine structures of excitonic states in monolayer TMDCs, with a focus on tungsten-based TMDCs and related alloy. Many of the new excitonic complexes inherit the valley degree of freedom, and the valley-polarized dark excitonic states are of particular interest because of their long lifetime and possible long valley coherence time. The capability of resolving the excitonic fine structures also enables the investigation of exciton–phonon interactions. The knowledge of the interlayer between excitons and other particles not only advances our understanding of many-body effects in the monolayer TMDCs but also provides guidance on future applications based on TMDCs.

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.

Sign in / Sign up

Export Citation Format

Share Document