From Single Atoms to Engineered “Super-Atoms”: Interfacing Photons and Atoms in Free Space

Advances in Optics ◽

10.1155/2014/572084 ◽

2014 ◽

Vol 2014 ◽

pp. 1-28 ◽

Cited By ~ 1

Author(s):

Yevhen Miroshnychenko

Keyword(s):

Laser Cooling ◽

Quantum Communication ◽

Single Photon ◽

Experimental Methods ◽

Quantum Systems ◽

Single Atom ◽

Laser Cooling And Trapping ◽

Single Atoms ◽

Quantum Properties ◽

Collective Levels

During the last decades the development of laser cooling and trapping has revolutionized the field of quantum optics. Now we master techniques to control the quantum properties of atoms and light, even at a single atom and single photon level. Understanding and controlling interactions of atoms and light both on the microscopic single particle and on the macroscopic collective levels, are two of the very active directions of the current research in this field. The goal is to engineer quantum systems with tailored properties designed for specific applications. One of the ambitious applications on this way is interfacing quantum information for quantum communication and quantum computing. We summarize here theoretical ideas and experimental methods for interfacing atom-based quantum memories with single flying photons.

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Tunable Carbon Surface from Mono- to Multi-Metallic Single Atoms

10.26434/chemrxiv.12264083 ◽

2020 ◽

Author(s):

Weihong Lai ◽

Heng Wang ◽

Quan jiang ◽

Zichao Yan ◽

Hanwen Liu ◽

...

Keyword(s):

Synergistic Effects ◽

Structural Evolution ◽

Charge Compensation ◽

Catalytic Reactions ◽

Single Atom ◽

Carbon Surface ◽

Hydrogen Electrode ◽

Single Atoms ◽

Mass Activity ◽

Co Doped

Herein, we develop a non-selective charge compensation strategy to prepare multi-single-atom doped carbon (MSAC) in which a sodium p-toluenesulfonate (PTS-Na) doped polypyrrole (S-PPy) polymer is designed to anchor discretionary mixtures of multiple metal cations, including iron (Fe3+), cobalt (Co3+), ruthenium (Ru3+), palladium (Pd2+), indium (In3+), iridium (Ir2+), and platinum (Pt2+) . As illustrated in Figure 1, the carbon surface can be tuned with different level of compositional complexities, including unary Pt1@NC, binary (MSAC-2, (PtFe)1@NC), ternary (MSAC-3, (PtFeIr)1@NC), quaternary (MSAC-4, (PtFeIrRu)1@NC), quinary (MSAC-5, (PtFeIrRuCo)1@NC), senary (MSAC-6, (PtFeIrRuCoPd)1@NC), and septenary (MSAC-7, (PtFeIrRuCoPdIn)1@NC) samples. The structural evolution of carbon surface dictates the activities of both ORR and HER. The senary MSAC-6 achieves the ORR mass activity of 18.1 A·mgmetal-1 at 0.9 V (Vs reversible hydrogen electrode (RHE)) over 30K cycles, which is 164 times higher than that of commercial Pt/C. The quaternary MSAC-4 presented a comparable HER catalytic capability with that of Pt/C. These results indicate that the highly complexed carbon surface can enhance its ability over general electrochemical catalytic reactions. The mechanisms regarding of the ORR and HER activities of the alternated carbon surface are also theoretically and experimentally investigated in this work, showing that the synergistic effects amongst the co-doped atoms can activate or inactivate certain single-atom sites.

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Improving peroxymonosulfate activation by copper ion-saturated adsorbent-based single atom catalysts for the degradation of organic contaminants: electron-transfer mechanism and the key role of Cu single atoms

Journal of Materials Chemistry A ◽

10.1039/d1ta02237g ◽

2021 ◽

Author(s):

Jingwen Pan ◽

Baoyu Gao ◽

Pijun Duan ◽

Kangying Guo ◽

Muhammad Akram ◽

...

Keyword(s):

Electron Transfer ◽

Organic Contaminants ◽

High Salinity ◽

Copper Ion ◽

Single Atom ◽

Electron Transfer Mechanism ◽

Persulfate Oxidation ◽

Single Atoms ◽

Oxidation Technology

Nonradical pathway-based persulfate oxidation technology is considered to be a promising method for high-salinity organic wastewater treatment.

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Multiparticle quantum plasmonics

Nanophotonics ◽

10.1515/nanoph-2019-0517 ◽

2020 ◽

Vol 9 (6) ◽

pp. 1243-1269 ◽

Cited By ~ 2

Author(s):

Chenglong You ◽

Apurv Chaitanya Nellikka ◽

Israel De Leon ◽

Omar S. Magaña-Loaiza

Keyword(s):

Quantum Dynamics ◽

Degrees Of Freedom ◽

Single Photon ◽

Quantum Systems ◽

Many Body ◽

Statistical Fluctuations ◽

Quantum Plasmonics ◽

Control Of Quantum Systems ◽

Multiparticle Systems ◽

Quantum Photonics

AbstractA single photon can be coupled to collective charge oscillations at the interfaces between metals and dielectrics forming a single surface plasmon. The electromagnetic near-fields induced by single surface plasmons offer new degrees of freedom to perform an exquisite control of complex quantum dynamics. Remarkably, the control of quantum systems represents one of the most significant challenges in the field of quantum photonics. Recently, there has been an enormous interest in using plasmonic systems to control multiphoton dynamics in complex photonic circuits. In this review, we discuss recent advances that unveil novel routes to control multiparticle quantum systems composed of multiple photons and plasmons. We describe important properties that characterize optical multiparticle systems such as their statistical quantum fluctuations and correlations. In this regard, we discuss the role that photon-plasmon interactions play in the manipulation of these fundamental properties for multiparticle systems. We also review recent works that show novel platforms to manipulate many-body light-matter interactions. In this spirit, the foundations that will allow nonexperts to understand new perspectives in multiparticle quantum plasmonics are described. First, we discuss the quantum statistical fluctuations of the electromagnetic field as well as the fundamentals of plasmonics and its quantum properties. This discussion is followed by a brief treatment of the dynamics that characterize complex multiparticle interactions. We apply these ideas to describe quantum interactions in photonic-plasmonic multiparticle quantum systems. We summarize the state-of-the-art in quantum devices that rely on plasmonic interactions. The review is concluded with our perspective on the future applications and challenges in this burgeoning field.

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Fundamental limitations on distillation of quantum channel resources

Nature Communications ◽

10.1038/s41467-021-24699-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Bartosz Regula ◽

Ryuji Takagi

Keyword(s):

Lower Bounds ◽

Quantum Channel ◽

Quantum Communication ◽

Fault Tolerant ◽

State Of The Art ◽

Quantum Systems ◽

Noisy Channels ◽

General Transformation ◽

Fundamental Limitations ◽

Strong Converse

AbstractQuantum channels underlie the dynamics of quantum systems, but in many practical settings it is the channels themselves that require processing. We establish universal limitations on the processing of both quantum states and channels, expressed in the form of no-go theorems and quantitative bounds for the manipulation of general quantum channel resources under the most general transformation protocols. Focusing on the class of distillation tasks — which can be understood either as the purification of noisy channels into unitary ones, or the extraction of state-based resources from channels — we develop fundamental restrictions on the error incurred in such transformations, and comprehensive lower bounds for the overhead of any distillation protocol. In the asymptotic setting, our results yield broadly applicable bounds for rates of distillation. We demonstrate our results through applications to fault-tolerant quantum computation, where we obtain state-of-the-art lower bounds for the overhead cost of magic state distillation, as well as to quantum communication, where we recover a number of strong converse bounds for quantum channel capacity.

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Observing quantum coherence from photons scattered in free-space

Light Science & Applications ◽

10.1038/s41377-021-00565-y ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Shihan Sajeed ◽

Thomas Jennewein

Keyword(s):

Free Space ◽

Quantum Coherence ◽

Quantum Communication ◽

Single Photon ◽

Detector Array ◽

Line Of Sight ◽

Background Suppression ◽

Single Photon Detector ◽

High Background ◽

Non Line Of Sight

AbstractQuantum channels in free-space, an essential prerequisite for fundamental tests of quantum mechanics and quantum technologies in open space, have so far been based on direct line-of-sight because the predominant approaches for photon-encoding, including polarization and spatial modes, are not compatible with randomly scattered photons. Here we demonstrate a novel approach to transfer and recover quantum coherence from scattered, non-line-of-sight photons analyzed in a multimode and imaging interferometer for time-bins, combined with photon detection based on a 8 × 8 single-photon-detector-array. The observed time-bin visibility for scattered photons remained at a high 95% over a wide scattering angle range of −450 to +450, while the individual pixels in the detector array resolve or track an image in its field of view of ca. 0.5°. Using our method, we demonstrate the viability of two novel applications. Firstly, using scattered photons as an indirect channel for quantum communication thereby enabling non-line-of-sight quantum communication with background suppression, and secondly, using the combined arrival time and quantum coherence to enhance the contrast of low-light imaging and laser ranging under high background light. We believe our method will instigate new lines for research and development on applying photon coherence from scattered signals to quantum sensing, imaging, and communication in free-space environments.

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Synergy of Single Atoms Pd and Oxygen Vacancies on In2O3 for Highly Selective C1 Oxygenates Production from Methane under Visible Light

10.21203/rs.3.rs-942037/v1 ◽

2021 ◽

Author(s):

Lei Luo ◽

Lei Fu ◽

Huifen Liu ◽

Youxun Xu ◽

Jialiang Xing ◽

...

Keyword(s):

Oxygen Vacancies ◽

Single Atom ◽

Electron Transfer Pathway ◽

Mild Conditions ◽

Single Atoms ◽

Primary Products ◽

Critical Issues ◽

Regulation Of Activity ◽

Visible Irradiation ◽

Dft Modelling

Abstract Methane (CH4) oxidation to high value chemicals under mild conditions through photocatalysis is a sustainable and appealing pathway, nevertheless confronting the critical issues on both conversion and selectivity. Herein, under visible irradiation (420 nm), the synergy of palladium (Pd) atom cocatalyst and oxygen vacancies (OVs) on In2O3 nanorods enabled superior photocatalytic CH4 activation by O2. The optimised catalyst reached ca. 100 µmol·h− 1 of C1 oxygenates, with a selectivity of primary products (CH3OH and CH3OOH) up to 82.5 %. Mechanism investigation elucidated that such superior photocatalysis was induced by the dedicated function of Pd single atoms and oxygen vacancies on boosting hole and electron transfer pathway, respectively. O2 was proven to be the only oxygen source for CH3OH production, while H2O acted as the promoter for efficient CH4 activation through ·OH production and facilitated product desorption as indicated by DFT modelling. This work thus provides new understandings on simultaneous regulation of activity and selectivity by the significant synergy of single atom cocatalysts and oxygen vacancies.

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Interview with 2012 Nobel Prize Winner Serge Haroche

Asia Pacific Physics Newsletter ◽

10.1142/s2251158x13000106 ◽

2013 ◽

Vol 02 (01) ◽

pp. 51-53

Keyword(s):

Nobel Prize ◽

Quantum Physics ◽

Annual Report ◽

Experimental Methods ◽

Nobel Prize Winner ◽

Quantum Systems ◽

Collège De France ◽

Lecture Series ◽

National University ◽

Nobel Prize In Physics

Serge Haroche, Chair in Quantum Physics at the College de France, won a share of the Nobel Prize in Physics 2012. Before the prize was announced, the Centre for Quantum Technologies (CQT) at the National University of Singapore had invited him to contribute to its 2012 annual report. This was after he delivered his prestigious College de France lecture series in Singapore in 2012. The Q&A was published in full on CQT's website and is reproduced here with permission. Serge Haroche was awarded the Nobel Prize in Physics 2012 "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems."

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