Now showing items 1-20 of 36

  • Accumulation-based computing using phasechange memories with FET access devices 

    Hosseini, Peiman; Sebastian, A.; Papandreou, N.; Wright, C. David; Bhaskaran, Harish (Institute of Electrical and Electronics Engineers (IEEE), 2015-07-15)
    Phase-change materials and devices have received much attention as a potential route to the realization of various types of unconventional computing paradigms. In this letter, we present non-von Neumann arithmetic processing ...
  • An analytical model for nanoscale electrothermal probe recording on phase-change media 

    Aziz, Mustafa M.; Wright, C. David (American Institute of Physics, 2006)
    Scanning probe memories are now emerging as a means of achieving nanoscale resolution data storage. The use of microscopic conductive tips in contact with a phase-change material to record data as amorphous and crystalline ...
  • Crystallization of Ge2Sb2Te5 films by amplified femtosecond optical pulses 

    Liu, Y.; Aziz, Mustafa M.; Shalini, Ashawaraya; Wright, C. David; Hicken, R.J. (American Institute of Physics, 2012)
    The phase transition between the amorphous and crystalline states of Ge2Sb2Te5 has been studied by exposure of thin films to series of 60 femtosecond (fs) amplified laser pulses. The analysis of microscope images of marks ...
  • Dataset of Observation of T2-like coherent optical phonons in epitaxial Ge2Sb2Te5/GaSb(001) films 

    Shalini, Ashawaraya; Liu, Y.; Al-Jarah, Uday Ali Sabeeh; Srivastava, G.P.; Wright, C. David; Katmis, F.; Braun, W.; Hicken, R.J. (University of Exeter, 2013-10-04)
    The phonon spectrum of Ge2Sb2Te5 is a signature of its crystallographic structure and underlies the phase transition process used in memory applications. Epitaxial materials allow coherent optical phonons to be studied in ...
  • The Design of Re-writeable Ultra-High Density Scanning-Probe Phase-Change Memories 

    Wright, C. David; Wang, Lei; Shah, P.; Aziz, Mustafa M.; Varesi, E.; Bez, R.; Moroni, M.; Cazzaniga, F. (Institute of Electrical and Electronics Engineers (IEEE), 2010)
    A systematic design of practicable media suitable for rewritable, ultrahigh density (>;1Tbit/sq.in.), high data rate (>;1Mbit/s/tip) scanning-probe phase-change memories is presented. The basic design requirements were met ...
  • Design, development and testing of multi-functional non-linear ultrasonic instrumentation for the detection of defects and damage in CFRP materials and structures 

    Armitage, Peter R.; Wright, C. David (Elsevier, 2013)
    A multi-functional non-linear ultrasonic testing approach is presented for in situ and ex-situ detection of a variety of defects (e.g. micro-cracking, delamination and disbonding) induced by various damage mechanisms ...
  • The effect of thermal anisotropies during crystallization in phase-change recording media 

    Belmont, M.R.; Aziz, Mustafa M.; Wright, C. David (American Institute of Physics, 2008)
    The problem discussed is the significance of anisotropies in the thermal parameters of different phases of phase-change materials as used for data storage purposes during recording. The particular phase change in interest ...
  • Fast simulation of phase-change processes in chalcogenide alloys using a Gillespie-type cellular automata approach 

    Ashwin, Peter; Patnaik, B. S. V.; Wright, C. David (American Institute of Physics, 2008)
    A stochastic cellular automata simulator capable of spatiotemporal modeling of the crystallization and amorphization behavior of phase-change materials during the complex annealing cycles used in optical and electrical ...
  • Front propagation in a phase field model with phase-dependent heat absorption 

    Blyuss, Konstantin; Ashwin, Peter; Wright, C. David; Bassom, Andrew P. (Elsevier, 2006)
    We present a model for the spatio-temporal behaviour of films exposed to radiative heating, where the film can change reversibly between amorphous (glassy) and crystalline states. Such phase change materials are used ...
  • Integrated all-photonic non-volatile multi-level memory 

    Rios, Carlos; Stegmaier, Matthias; Hosseini, Peiman; Wang, Di; Scherer, Torsten; Wright, C. David; Bhaskaran, Harish; Pernice, Wolfram H.P. (Nature Publishing Group, 2015-09-21)
    Implementing on-chip non-volatile photonic memories has been a long-term, yet elusive goal. Photonic data storage would dramatically improve performance in existing computing architectures1 by reducing the latencies ...
  • Localised electro-thermal processing: a new route to the patterning of magnetic recording media 

    Aziz, Mustafa M.; Newman, Dave M.; Sidwell, A; Wears, M. Lesley; Wright, C. David (Institute of Physics, 2010-11-23)
    Previous reports have detailed the fabrication of media able to support high density magnetic recording in both longitudinal and perpendicular formats by the global rapid thermal processing of sputtered non-magnetic precursor ...
  • Master-equation approach to the study of phase-change processes in data storage media 

    Blyuss, Konstantin; Ashwin, Peter; Bassom, Andrew P.; Wright, C. David (American Physical Society, 2005)
    We study the dynamics of crystallization in phase-change materials using a master-equation approach in which the state of the crystallizing material is described by a cluster size distribution function. A model is developed ...
  • Master-equation approach to understanding multistate phase-change memories and processors 

    Wright, C. David; Blyuss, Konstantin; Ashwin, Peter (American Institute of Physics, 2007)
    A master-equation approach is used to perform dynamic modeling of phase-transformation processes that define the operating regimes and performance attributes of electronic (and optical) processors and multistate memory ...
  • Mixed-Mode Electro Optical Properties of Ge2Sb2Te5 

    Rodriguez-Hernandez, G; Hosseini, Peiman; Au, YY; Pernice, Wolfram H.P.; Wright, C. David; Bhaskaran, Harish (-, 2013)
    In this paper we present ongoing work on a novel alternative mode of operation of phase change materials, specifically Ge2Sb2Te5: mixed-mode electro-optical operation, which offers a new set of potential applications for ...
  • A model for multilevel phase-change memories incorporating resistance drift effects 

    Cobley, RA; Wright, C. David; Vazquez Diosdado, JA (Institute of Electrical and Electronics Engineers (IEEE), 2014-09-12)
    Phase change memories are emerging as a most promising technology for future nonvolatile, solid-state, electrical storage. However, to compete effectively in mainstream storage applications, a multilevel cell capability ...
  • A model for the phase-change process in GeSbTe thin films used for optical and electrical data storage 

    Senkader, Semih; Aziz, Mustafa M.; Wright, C. David (SPIE, 2003)
    We have developed a model to simulate the phase-change behavior of GeSbTe thin film alloys. Based on classical nucleation theory we described formation of crystalline clusters using chemical rate equations. Assuming that ...
  • New 'Mixed-Mode' Optoelectronic Applications Possibilities using Phase-Change Materials and Devices 

    Wright, C. David; Au, Y.; Bhaskaran, Harish; Rodriguez-Hernandez, G; Hosseini, Peiman; Rios, Carlos; Agarwal, R; Pernice, Wolfram H.P. (Materials Research Society, 2015-04-09)
    To date the main applications of phase-change materials and devices have been limited to the provision of non-volatile memories. Recently, however, the potential has been demonstrated for using a phase-change approach for ...
  • Novel applications possibilities for phase-change materials and devices 

    Wright, C. David; Au, YY; Aziz, Mustafa M.; Bhaskaran, Harish; Cobley, Rosie; Rodriguez-Hernandez, G; Hosseini, Peiman; Pernice, Wolfram H.P.; Wang, L (The authors, 2013)
    Phase-change materials and devices are most widely known for their use in optical and electrical non-volatile memory applications. Recently however the potential has been demonstrated for using phase-change materials and ...
  • Observation of T2-like coherent optical phonons in epitaxial Ge2Sb2Te5/GaSb(001) films 

    Shalini, Ashawaraya; Liu, Y.; Al-Jarah, Uday Ali Sabeeh; Srivastava, G.P.; Wright, C. David; Katmis, F.; Braun, W.; Hicken, R.J. (Nature Publishing Group, 2013)
    The phonon spectrum of Ge2Sb2Te5 is a signature of its crystallographic structure and underlies the phase transition process used in memory applications. Epitaxial materials allow coherent optical phonons to be studied in ...
  • On-chip photonic memory elements employing phase-change materials 

    Rios, Carlos; Hosseini, Peiman; Wright, C. David; Bhaskaran, Harish; Pernice, Wolfram H.P. (Wiley, 2013)
    Phase-change materials integrated into nanophotonic circuits provide a flexible way to realize tunable optical components. Relying on the enormous refractive-index contrast between the amorphous and crystalline states, ...