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Complex networks in finance

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Editorial

Focus on Complex networks in finance

Net gains p119

doi:10.1038/nphys2588

Physics — and physicists — have had much to contribute to economic and finance. Now the science of complex networks sets a way forward to understanding and managing the complex financial networks of the world's markets.


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Commentaries

Focus on Complex networks in finance

Network opportunity pp121 - 123

Michele Catanzaro & Mark Buchanan

doi:10.1038/nphys2570

Our developing scientific understanding of complex networks is being usefully applied in a wide set of financial systems. What we've learned from the 2008 crisis could be the basis of better management of the economy — and a means to avert future disaster.

Subject term: Statistical physics, thermodynamics and nonlinear dynamics


Focus on Complex networks in finance

Complex derivatives pp123 - 125

Stefano Battiston, Guido Caldarelli, Co-Pierre Georg, Robert May & Joseph Stiglitz

doi:10.1038/nphys2575

The intrinsic complexity of the financial derivatives market has emerged as both an incentive to engage in it, and a key source of its inherent instability. Regulators now faced with the challenge of taming this beast may find inspiration in the budding science of complex systems.

Subject term: Statistical physics, thermodynamics and nonlinear dynamics


Focus on Complex networks in finance

Reconstructing a credit network pp125 - 126

Guido Caldarelli, Alessandro Chessa, Fabio Pammolli, Andrea Gabrielli & Michelangelo Puliga

doi:10.1038/nphys2580

The science of complex networks can be usefully applied in finance, although there is limited data available with which to develop our understanding. All is not lost, however: ideas from statistical physics make it possible to reconstruct details of a financial network from partial sets of information.

Subject term: Statistical physics, thermodynamics and nonlinear dynamics


Focus on Complex networks in finance

The power to control pp126 - 128

Marco Galbiati, Danilo Delpini & Stefano Battiston

doi:10.1038/nphys2581

Understanding something of the complexity of a financial network is one thing, influencing the behaviour of that system is another. But new tools from network science define a notion of 'controllability' that, coupled with 'centrality', could prove useful to economists and financial regulators.

Subject term: Statistical physics, thermodynamics and nonlinear dynamics


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Thesis

Size and supersize p129

Mark Buchanan

doi:10.1038/nphys2574


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News and Views

Astrophysics: An unexpected shock pp131 - 132

Ian G. Richardson

doi:10.1038/nphys2565

Observations made by the Cassini spacecraft at the bow shock of Saturn suggest that electrons are likely to be accelerated to near-relativistic energies by strong astrophysical shocks.

Subject terms: Plasma physics | Astrophysics

See also: Letter by Masters et al.


Astronomy: The wise hunter p132

May Chiao

doi:10.1038/nphys2578

Subject term: Astrophysics


Complex networks: Synchrony and your morning coffee pp133 - 134

Ian Dobson

doi:10.1038/nphys2559

Networks as complex as national power grids must be stable enough to maintain synchrony in order to function. Understanding how this stability is achieved forms the focus of a new study that holds promise for improving grid performance.

Subject term: Statistical physics, thermodynamics and nonlinear dynamics

See also: Article by Motter et al.


Biomechanics: Have legs will travel p134

Abigail Klopper

doi:10.1038/nphys2579

Subject term: Biological physics


Condensed matter: Graphene's topological insulation pp135 - 136

Chun Ning (Jeanie) Lau

doi:10.1038/nphys2567

A quantum phase transition from an antiferromagnetic to a ferromagnetic state suggests that bilayer graphene can exhibit properties analogous to those seen in topological insulators.

Subject terms: Condensed-matter physics | Materials physics

See also: Letter by Maher et al.


Quantum engineering: Diamond envy pp136 - 137

Joshua Nunn

doi:10.1038/nphys2563

Nitrogen atoms trapped tens of nanometres apart in diamond can now be linked by quantum entanglement. This ability to produce and control entanglement in solid systems could enable powerful quantum computers.

Subject terms: Condensed-matter physics | Quantum physics

See also: Letter by Dolde et al.


Quantum interferometry: Matter waves in a new light pp137 - 138

Alexander D. Cronin & William F. Holmgren

doi:10.1038/nphys2562

Ionizing radiation can diffract molecules and demonstrate a novel matter-wave interferometer. Ionization gratings may now enable quantum interference with heavier particles and interferometric measurements with higher precision.

Subject terms: Quantum physics | Atomic and molecular physics

See also: Letter by Haslinger et al.


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Letters

Room-temperature entanglement between single defect spins in diamond pp139 - 143

F. Dolde, I. Jakobi, B. Naydenov, N. Zhao, S. Pezzagna, C. Trautmann, J. Meijer, P. Neumann, F. Jelezko & J. Wrachtrup

doi:10.1038/nphys2545

Engineered defects in the diamond lattice hold promise for the storage and manipulation of quantum information. Entanglement between the electron and nuclear spins of two such defects is demonstrated at room temperature.

Subject terms: Condensed-matter physics | Quantum physics

See also: News and Views by Nunn


A universal matter-wave interferometer with optical ionization gratings in the time domain pp144 - 148

Philipp Haslinger, Nadine Dörre, Philipp Geyer, Jonas Rodewald, Stefan Nimmrichter & Markus Arndt

doi:10.1038/nphys2542

A matter-wave interferometer is ‘universal’ if it can be applied to any atom or molecule irrespective of its internal state. This removes the need to prepare a spatially coherent incident beam. Such a system is now realized using three separate optical ionization gratings, and interference of molecular clusters with a de Broglie wavelength as small as 275 fm is demonstrated.

Subject terms: Atomic and molecular physics | Quantum physics | Techniques and instrumentation

See also: News and Views by Cronin & Holmgren


Electrical tuning of valley magnetic moment through symmetry control in bilayer MoS2 pp149 - 153

Sanfeng Wu, Jason S. Ross, Gui-Bin Liu, Grant Aivazian, Aaron Jones, Zaiyao Fei, Wenguang Zhu, Di Xiao, Wang Yao, David Cobden & Xiaodong Xu

doi:10.1038/nphys2524

Electric fields can break the structural inversion symmetry in bilayer 2D materials, providing a way of tuning the magnetic moment and Berry curvature. This effect can be probed directly in bilayer MoS2 using optical measurements.

Subject terms: Condensed-matter physics | Materials physics


Evidence for a spin phase transition at charge neutrality in bilayer graphene pp154 - 158

P. Maher, C. R. Dean, A. F. Young, T. Taniguchi, K. Watanabe, K. L. Shepard, J. Hone & P. Kim

doi:10.1038/nphys2528

A quantum phase transition from an antiferromagnetic to a ferromagnetic state is now measured in graphene bilayers. This observation supports the idea that bilayer graphene can sustain counter-propagating spin-polarized edge modes in analogy to the quantum spin Hall effect seen in topological insulators.

Subject terms: Condensed-matter physics | Materials physics

See also: News and Views by Lau


Manipulation of quantum paths for space–time characterization of attosecond pulses pp159 - 163

Kyung Taec Kim, Chunmei Zhang, Andrew D. Shiner, Sean E. Kirkwood, Eugene Frumker, Genevieve Gariepy, Andrei Naumov, D. M. Villeneuve & P. B. Corkum

doi:10.1038/nphys2525

An all-optical method to measure the space–time characteristics of an isolated attosecond pulse, without temporal and spatial averaging, is now demonstrated. The approach will provide further insight into the generation of ultrafast light, and may possibly be used to finely control the pulse characteristics.

Subject term: Optical physics


Electron acceleration to relativistic energies at a strong quasi-parallel shock wave pp164 - 167

A. Masters, L. Stawarz, M. Fujimoto, S. J. Schwartz, N. Sergis, M. F. Thomsen, A. Retinò, H. Hasegawa, B. Zieger, G. R. Lewis, A. J. Coates, P. Canu & M. K. Dougherty

doi:10.1038/nphys2541

Data from the Cassini spacecraft identify strong electron acceleration as the solar wind approaches the magnetosphere of Saturn. This so-called bow shock unexpectedly occurs even when the magnetic field is roughly parallel to the shock-surface normal. Knowledge of the magnetic dependence of electron acceleration will aid understanding of supernova remnants.

Subject terms: Astrophysics | Plasma physics

See also: News and Views by Richardson


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Articles

A large-scale quantum simulator on a diamond surface at room temperature pp168 - 173

Jianming Cai, Alex Retzker, Fedor Jelezko & Martin B. Plenio

doi:10.1038/nphys2519

Controllable quantum systems can be used to emulate intractable quantum many-body problems, but such simulators remain an experimental challenge. Nuclear spins on a diamond surface promise an improved large-scale quantum simulator operating at room temperature.

Subject terms: Condensed-matter physics | Quantum physics


Linked attosecond phase interferometry for molecular frame measurements pp174 - 178

J. B. Bertrand, H. J. Wörner, P. Salières, D. M. Villeneuve & P. B. Corkum

doi:10.1038/nphys2540

High-harmonic spectroscopy provides attosecond-scale information about optical processes in molecules. Present techniques, however, cannot simultaneously measure the phase as a function of molecular angle and photon frequency. An approach that retrieves both the amplitude and the phase of high-harmonic emission is now demonstrated, and could enable a full reconstruction of the molecular wavefunction.

Subject terms: Optical physics | Atomic and molecular physics


Slowing, advancing and switching of microwave signals using circuit nanoelectromechanics pp179 - 184

X. Zhou, F. Hocke, A. Schliesser, A. Marx, H. Huebl, R. Gross & T. J. Kippenberg

doi:10.1038/nphys2527

A nanomechanical oscillator coupled to a superconducting waveguide provides all-microwave field-controlled tunable slowing and advancing of microwave signals, with millisecond distortion-free delay and negligible losses.

Subject terms: Optical physics | Nanotechnology


A compact laser-driven plasma accelerator for megaelectronvolt-energy neutral atoms pp185 - 190

R. Rajeev, T. Madhu Trivikram, K. P. M. Rishad, V. Narayanan, E. Krishnakumar & M. Krishnamurthy

doi:10.1038/nphys2526

A megaelectronvolt beam of atoms is now generated by ionizing argon clusters, and then neutralizing the ions using Rydberg atoms. The compact system demonstrates a high neutral yield, and could find an important application as a sensitive probe of matter.

Subject terms: Plasma physics | Optical physics | Atomic and molecular physics


Spontaneous synchrony in power-grid networks pp191 - 197

Adilson E. Motter, Seth A. Myers, Marian Anghel & Takashi Nishikawa

doi:10.1038/nphys2535

Power-grid networks must be synchronized in order to function. A condition for the stability of the synchronous state enables identification of network parameters that enhance spontaneous synchronization—heralding the possibility of smart grids that operate optimally in real-world systems.

Subject term: Statistical physics, thermodynamics and nonlinear dynamics

See also: News and Views by Dobson


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