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Author Argyropoulos, T.; Catalan-Lasheras, N.; Grudiev, A.; Mcmonagle, G.; Rodriguez-Castro, E.; Syrachev, I.; Wegner, R.; Woolley, B.; Wuensch, W.; Zha, H.; Dolgashev, V.; Bowden, G.; Haase, A.; Lucas, T.G.; Volpi, M.; Esperante-Pereira, D.; Rajamaki, R.
Title Design, fabrication, and high-gradient testing of an X-band, traveling-wave accelerating structure milled from copper halves Type Journal Article
Year 2018 Publication Physical Review Accelerators and Beams Abbreviated Journal Phys. Rev. Accel. Beams
Volume 21 Issue 6 Pages 061001 - 11pp
Keywords
Abstract A prototype 11.994 GHz, traveling-wave accelerating structure for the Compact Linear Collider has been built, using the novel technique of assembling the structure from milled halves. The use of milled halves has many advantages when compared to a structure made from individual disks. These include the potential for a reduction in cost, because there are fewer parts, as well as a greater freedom in choice of joining technology because there are no rf currents across the halves' joint. Here we present the rf design and fabrication of the prototype structure, followed by the results of the high-power test and post-test surface analysis. During high-power testing the structure reached an unloaded gradient of 100 MV/m at a rf breakdown rate of less than 1.5 x 10(-5) breakdowns/pulse/m with a 200 ns pulse. This structure has been designed for the CLIC testing program but construction from halves can be advantageous in a wide variety of applications.
Address (up) [Argyropoulos, Theodoros; Catalan-Lasheras, Nuria; Grudiev, Alexej; Mcmonagle, Gerard; Rodriguez-Castro, Enrique; Syrachev, Igor; Wegner, Rolf; Woolley, Ben; Wuensch, Walter; Zha, Hao] CERN, European Org Nucl Res, CH-1211 Geneva, Switzerland, Email: thomas.geoffrey.lucas@cern.ch
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9888 ISBN Medium
Area Expedition Conference
Notes WOS:000434469900001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3608
Permanent link to this record
 

 
Author Arnault, P.; Di Molfetta, G.; Brachet, M.; Debbasch, F.
Title Quantum walks and non-Abelian discrete gauge theory Type Journal Article
Year 2016 Publication Physical Review A Abbreviated Journal Phys. Rev. A
Volume 94 Issue 1 Pages 012335 - 6pp
Keywords
Abstract A family of discrete-time quantum walks (DTQWs) on the line with an exact discrete U(N) gauge invariance is introduced. It is shown that the continuous limit of these DTQWs, when it exists, coincides with the dynamics of a Dirac fermion coupled to usual U(N) gauge fields in two-dimensional spacetime. A discrete generalization of the usual U(N) curvature is also constructed. An alternate interpretation of these results in terms of superimposed U(1) Maxwell fields and SU(N) gauge fields is discussed in the Appendix. Numerical simulations are also presented, which explore the convergence of the DTQWs towards their continuous limit and which also compare the DTQWs with classical (i.e., nonquantum) motions in classical SU(2) fields. The results presented in this paper constitute a first step towards quantum simulations of generic Yang-Mills gauge theories through DTQWs.
Address (up) [Arnault, Pablo; Debbasch, Fabrice] Univ Paris 06, Univ Paris 04, PSL Res Univ, LERMA,Observ Paris,CNRS,UMR 8112, F-75014 Paris, France, Email: pablo.arnault@upmc.fr;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9926 ISBN Medium
Area Expedition Conference
Notes WOS:000380095000005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2761
Permanent link to this record
 

 
Author Arnault, P.; Pepper, B.; Perez, A.
Title Quantum walks in weak electric fields and Bloch oscillations Type Journal Article
Year 2020 Publication Physical Review A Abbreviated Journal Phys. Rev. A
Volume 101 Issue 6 Pages 062324 - 12pp
Keywords
Abstract Bloch oscillations appear when an electric field is superimposed on a quantum particle that evolves on a lattice with a tight-binding Hamiltonian (TBH), i.e., evolves via what we call an electric TBH; this phenomenon will be referred to as TBH Bloch oscillations. A similar phenomenon is known to show up in so-called electric discrete-time quantum walks (DQWs) [C. Cedzich et al., Phys. Rev. Lett. 111, 160601 (2013);] this phenomenon will be referred to as DQW Bloch oscillations. This similarity is particularly salient when the electric field of the DQW is weak. For a wide, i.e., spatially extended, initial condition, one numerically observes semiclassical oscillations, i.e., oscillations of a localized particle, for both the electric TBH and the electric DQW. More precisely, the numerical simulations strongly suggest that the semiclassical DQW Bloch oscillations correspond to two counterpropagating semiclassical TBH Bloch oscillations. In this work it is shown that, under certain assumptions, the solution of the electric DQW for a weak electric field and a wide initial condition is well approximated by the superposition of two continuous-time expressions, which are counterpropagating solutions of an electric TBH whose hopping amplitude is the cosine of the arbitrary coin-operator mixing angle. In contrast, if one wishes the continuous-time approximation to hold for spatially localized initial conditions, one needs at least the DQW to be lazy, as suggested by numerical simulations and by the fact that this has been proven in the case of a vanishing electric field [F. W. Strauch, Phys. Rev. A 74, 030301(R) (2006)].
Address (up) [Arnault, Pablo; Pepper, Benjamin; Perez, A.] Univ Valencia, CSIC, Dept Fis Teor, Cerrer Dr Moliner 50, Burjassot 46100, Spain, Email: pablo.arnault@ific.uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1050-2947 ISBN Medium
Area Expedition Conference
Notes WOS:000541400900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4431
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Author Arnault, P.; Perez, A.; Arrighi, P.; Farrelly, T.
Title Discrete-time quantum walks as fermions of lattice gauge theory Type Journal Article
Year 2019 Publication Physical Review A Abbreviated Journal Phys. Rev. A
Volume 99 Issue 3 Pages 032110 - 16pp
Keywords
Abstract It is shown that discrete-time quantum walks can be used to digitize, i.e., to time discretize fermionic models of continuous-time lattice gauge theory. The resulting discrete-time dynamics is thus not only manifestly unitary, but also ultralocal, i.e., the particle's speed is upper bounded, as in standard relativistic quantum field theories. The lattice chiral symmetry of staggered fermions, which corresponds to a translational invariance, is lost after the requirement of ultralocality of the evolution; this fact is an instance of Meyer's 1996 no-go results stating that no nontrivial scalar quantum cellular automaton can be translationally invariant [D. A. Meyer, J. Stat. Phys. 85, 551 (1996); Phys. Lett. A 223, 337 (1996)]. All results are presented in a single-particle framework and for a (1+1)-dimensional space-time.
Address (up) [Arnault, Pablo; Perez, Armando] Univ Valencia, Dept Fis Teor, Dr Moliner 50, E-46100 Burjassot, Spain, Email: pablo.arnault@ific.uv.es
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9926 ISBN Medium
Area Expedition Conference
Notes WOS:000461896700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3950
Permanent link to this record
 

 
Author Arrighi, P.; Di Molfetta, G.; Marquez-Martin, I.; Perez, A.
Title Dirac equation as a quantum walk over the honeycomb and triangular lattices Type Journal Article
Year 2018 Publication Physical Review A Abbreviated Journal Phys. Rev. A
Volume 97 Issue 6 Pages 062111 - 5pp
Keywords
Abstract A discrete-time quantum walk (QW) is essentially an operator driving the evolution of a single particle on the lattice, through local unitaries. Some QWs admit a continuum limit, leading to well-known physics partial differential equations, such as the Dirac equation. We show that these simulation results need not rely on the grid: the Dirac equation in (2 + 1) dimensions can also be simulated, through local unitaries, on the honeycomb or the triangular lattice, both of interest in the study of quantum propagation on the nonrectangular grids, as in graphene-like materials. The latter, in particular, we argue, opens the door for a generalization of the Dirac equation to arbitrary discrete surfaces.
Address (up) [Arrighi, Pablo; Di Molfetta, Giuseppe; Marquez-Martin, Ivan] Aix Marseille Univ, Univ Toulon, LIS, CNRS, Marseille, France, Email: pablo.arrighi@univ-amu.fr;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9926 ISBN Medium
Area Expedition Conference
Notes WOS:000435076800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3624
Permanent link to this record