Most recent highlights from EPL:
Dispersed stable states spectrum of the wave equation with space-time periodic potential1
by B. S. Alexandrov, A. R. Bishop, N. Zahariev and I. Kostadinov
We study the stable states of the wave equation with d-spatial and 1-time dimensions and with space-time periodic potential. The dispersed stable states spectrum of such (d+1) -periodic wave equation is due to the incommensurability of the speed of light and the ratio of space and time periods. A Bloch-Floquet analysis leads to a (d+1) -cube as a reduced Brillouin zone, but because of the speed incommensurability the stable states in this cube may form a spectrum of sets with a reduced dimensionality. For electromagnetic waves in photonic crystals the medium may amplify some waves with lengths fitting the crystal lattice. The energy from the external field can be pumped to the waves via the dipole moment oscillations.
Nonlocal current-voltage characteristics of gated superconducting sketched oxide nanostructures2
by J. P. Veazey, G. Cheng, S. Lu, M. Tomczyk, F. Bi, M. Huang, S. Ryu, C. W. Bark, K. H. Cho, C. B. Eom, P. Irvin and J. Levy
Effects from nonequilibrium superconductivity play a major role in the physics of superconducting nanoelectronics. Notably, charge imbalance arising from the point at which the superconducting device contacts normal-metal leads is prevalent, particularly in reduced dimensions. We investigate nonlocal transport signatures in quasi-1D nanostructures formed at the LaAlO3/SrTiO3 interface. The nonlocal resistances correlate with the bias, magnetic field, and back gate dependence of the superconducting state. We attribute these signatures to charge imbalance or spin-dependent excitations. Understanding and control over these effects are important for further development of superconducting nanoelectronics in this material system, including the ability to probe the interaction of superconductivity and other rich physics in LaAlO3/SrTiO3 on the nanoscale.
Antiferromagnetic long-range order in the uniform resonating valence bond state on the square lattice3
by Tao Li
With an extensive variational Monte Carlo simulation, we show that the uniform resonating valence bond (U-RVB) state on the square lattice is antiferromagnetic long-range ordered. The ordered moment is estimated to be m≈0.186. Such a behavior is quite unexpected from the slave boson mean-field treatment or the Gutzwiller approximation of the uniform RVB state.
Information erasure in copolymers4
by D. Andrieux and P. Gaspard
Information erasure at the molecular scale during the depolymerization of copolymers is shown to require a minimum entropy production in accordance with Landauer’s principle and as a consequence of the second law of thermodynamics. This general result is illustrated with an exactly solvable model of copolymerization, which also shows that the minimum entropy production that is possible for a specific molecular mechanism of depolymerization may be larger than the minimum required by Landauer’s principle.
Re-entrant magnetic-field–induced charge and spin gaps in the coupled dual-chain quasi–one-dimensional organic conductor perylene2[Pt(mnt)2]5
by L. E. Winter, J. S. Brooks, P. Schlottmann, M. Almeida, S. Benjamin and C. Bourbonnais
An inductive method is used to follow the magnetic-field–dependent susceptibility of the coupled charge density wave (CDW) and spin-Peierls (SP) ordered state behavior in the dual-chain organic conductor perylene2[Pt(mnt)2]. In addition to the coexisting SP-CDW state phase below 8 K and 20 T, the measurements show that a second spin-gapped phase appears above 20 T that coincides with a field-induced insulating phase. The results support a strong coupling of the CDW and SP order parameters even in high magnetic fields, and provide new insight into the nature of the magnetic susceptibility of dual-chain spin and charge systems.
- B. S. Alexandrov, A. R. Bishop, N. Zahariev and I. Kostadinov. 2013. Dispersed stable states spectrum of the wave equation with space-time periodic potential. EPL, 103, 50001. DOI: 10.1209/0295-5075/103/50001 [↩]
- J. P. Veazey, G. Cheng, S. Lu, M. Tomczyk, F. Bi, M. Huang, S. Ryu, C. W. Bark, K. H. Cho, C. B. Eom, P. Irvin and J. Levy. 2013. Nonlocal current-voltage characteristics of gated superconducting sketched oxide nanostructures. EPL, 103, 57001. DOI: 10.1209/0295-5075/103/57001 [↩]
- Tao Li. 2013. Antiferromagnetic long-range order in the uniform resonating valence bond state on the square lattice. EPL, 103, 57002. DOI: 10.1209/0295-5075/103/57002 [↩]
- D. Andrieux and P. Gaspard. 2013. Information erasure in copolymers. EPL, 103, 30004. DOI: 10.1209/0295-5075/103/30004 [↩]
- L. E. Winter, J. S. Brooks, P. Schlottmann, M. Almeida, S. Benjamin and C. Bourbonnais. 2013. Re-entrant magnetic-field–induced charge and spin gaps in the coupled dual-chain quasi–one-dimensional organic conductor perylene2[Pt(mnt)2]. EPL, 103, 37008. DOI: 10.1209/0295-5075/103/37008 [↩]