Nature Physics (NAT PHYS)

Publications in this journal

• Article: quantum biology

  Neill Lambert, Yueh-Nan Chen, Yuan-Chung Cheng, Che-Ming Li, Guang-Yin Chen, Franco Nori
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  ABSTRACT: Recent evidence suggests that a variety of organisms may harness some of the unique features of quantum mechanics to gain a biological advantage. These features go beyond trivial quantum effects and may include harnessing quantum coherence on physiologically important timescales. In this brief review we summarize the latest results for non-trivial quantum effects in photosynthetic light harvesting, avian magnetoreception and several other candidates for functional quantum biology. We present both the evidence for and arguments against there being a functional role for quantum coherence in these systems.
  Nature Physics 12/2012;
• Article: DISORDERED MEDIA: Beyond ballistic

  Marco Peccianti, Roberto Morandotti
  Nature Physics 11/2012;
• Article: Accessing long-lived nuclear singlet states between chemically equivalent spins without breaking symmetry.

  Yesu Feng, Ryan M Davis, Warren S Warren
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  ABSTRACT: Long-lived nuclear spin states could greatly enhance the applicability of hyperpolarized nuclear magnetic resonance. Using singlet states between inequivalent spin pairs has been shown to extend the signal lifetime by more than an order of magnitude compared to the spin lattice relaxation time (T 1), but they have to be prevented from evolving into other states. In the most interesting case the singlet is between chemically equivalent spins, as it can then be inherently an eigenstate. However this presents major challenges in the conversion from bulk magnetization to singlet. In the only case demonstrated so far, a reversible chemical reaction to break symmetry was required. Here we present a pulse sequence technique that interconverts between singlet spin order and bulk magnetization without breaking the symmetry of the spin system. This technique is independent of field strength and is applicable to a broad range of molecules.
  Nature Physics 11/2012; 8(11):831-837.
• Article: Strong-field physics with singular light beams

  M. Zürch, C. Kern, P. Hansinger, A. Dreischuh, C. Spielmann
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  ABSTRACT: Light beams carrying a point singularity with a screw-type phase distribution are associated with an optical vortex. The corresponding momentum flow leads to an orbital angular momentum of the photons. The study of optical vortices has led to applications such as particle micro-manipulation, imaging, interferometry, quantum information8 and high-resolution microscopy and lithography. Recent analyses showed that transitions forbidden by selection rules seem to be allowed when using optical vortex beams. To exploit these intriguing new applications, it is often necessary to shorten the wavelength by nonlinear frequency conversion. However, during the conversion the optical vortices tend to break up. Here we show that optical vortices can be generated in the extreme ultraviolet (XUV) region using high-harmonic generation. The singularity impressed on the fundamental beam survives the highly nonlinear process. Vortices in the XUV region have the same phase distribution as the driving field, which is in contradiction to previous findings, where multiplication of the momentum by the harmonic order is expected. This approach opens the way for several applications based on vortex beams in the XUV region.
  Nature Physics 10/2012; 8(10):743-746.
• Article: doi:10.1038/nphys2431

  Baker
  Nature Physics 09/2012;
• Article: The origin and non-quasiparticle nature of Fermi arcs in Bi2Sr2CaCu2O8+δ

  T. J. Reber, N. C. Plumb, Z. Sun, Y. Cao, Q. Wang, K. McElroy, H. Iwasawa, M. Arita, J. S. Wen, Z. J. Xu, G. Gu, Y. Yoshida, H. Eisaki, Y. Aiura, D. S. Dessau
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  ABSTRACT: A Fermi arc1, 2 is a disconnected segment of a Fermi surfaceobserved in the pseudogap phase3, 4 of cuprate superconductors. This simple description belies the fundamental inconsistency in the physics of Fermi arcs, specifically that such segments violate the topological integrity of the band5. Efforts to resolve this contradiction of experiment and theory have focused on connecting the ends of the Fermi arc back on itself to form a pocket, with limited and controversial success6, 7, 8, 9. Here we show the Fermi arc, although composed of real spectral weight, lacks the quasiparticles to be a true Fermi surface5. To reach this conclusion we developed a new photoemission-based technique that directly probes the interplay of pair-forming and pair-breaking processes with unprecedented precision. We find the spectral weight composing the Fermi arc is shifted from the gap edge to the Fermi energy by pair-breaking processes10. Although real, this weight does not form a true Fermi surface, because the quasiparticles, although significantly broadened, remain at the gap edge. This non-quasiparticle weight may account for much of the unexplained behaviour of the pseudogap phase of the cuprates.
  Nature Physics 08/2012; 8:606–610.
• Article: The energy-speed-accuracy tradeoff in sensory adaptation.

  Ganhui Lan, Pablo Sartori, Silke Neumann, Victor Sourjik, Yuhai Tu
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  ABSTRACT: Adaptation is the essential process by which an organism becomes better suited to its environment. The benefits of adaptation are well documented, but the cost it incurs remains poorly understood. Here, by analysing a stochastic model of a minimum feedback network underlying many sensory adaptation systems, we show that adaptive processes are necessarily dissipative, and continuous energy consumption is required to stabilize the adapted state. Our study reveals a general relation among energy dissipation rate, adaptation speed and the maximum adaptation accuracy. This energy-speed-accuracy relation is tested in the Escherichia coli chemosensory system, which exhibits near-perfect chemoreceptor adaptation. We identify key requirements for the underlying biochemical network to achieve accurate adaptation with a given energy budget. Moreover, direct measurements confirm the prediction that adaptation slows down as cells gradually de-energize in a nutrient-poor medium without compromising adaptation accuracy. Our work provides a general framework to study cost-performance tradeoffs for cellular regulatory functions and information processing.
  Nature Physics 05/2012; 8(5):422-428.
• Article: Quantum simulations with ultracold quantum gases

  Immanuel Bloch, Jean Dalibard, Sylvain
  Nature Physics 04/2012; 8(4):267-276.
• Article: Goals and opportunities in quantum simulation

  J. Ignacio Cirac, Peter Zoller
  Nature Physics 04/2012; 8(4):264-266.
• Article: Multistep redirection by cross-beam power transfer of ultrahigh-power lasers in a plasma

  J D Moody, P Michel, L Divol, R L Berger, E Bond, D K Bradley, D A Callahan, E L Dewald, S Dixit, M J Edwards, [......], M B Schneider, D J Strozzi, L J Suter, C A Thomas, R P J Town, K Widmann, E A Williams, L J Atherton, S H Glenzer, E I Moses
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  ABSTRACT: Laser redirection by cross-beam power transfer in a plasma is an important example of a nonlinear optics process which uses laser-plasma instabilities to one's advantage. We have demonstrated this in a hohlraum plasma at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. A four-wave mixing process causes laser power in multiple beams to change direction and add to the laser power of a selected beam. The process is controlled by setting the wavelength separation of the interacting laser beams. This technique provides a method to remotely re-point or combine high-powered laser beams without the need of local optical apparatus.
  Nature Physics 04/2012; 8(4):344-349.