Prof Arzhang Ardavan: Publications

Nanoscale solid-state quantum computing

Philosophical Transactions of the Royal Society A Mathematical Physical and Engineering Sciences 361:1808 (2003) 1473-1485

Authors:

A Ardavan, M Austwick, SC Benjamin, GAD Briggs, TJS Dennis, A Ferguson, DG Hasko, M Kanai, AN Khlobystov, BW Lovett, GW Morley, RA Oliver, DG Pettifor, K Porfyrakis, JH Reina, JH Rlce, JD Smith, RA Taylor, DA Williams, C Adelmann, H Mariette, RJ Hamers

Abstract:

Most experts agree that it is too early to say how quantum computers will eventually be built, and several nanoscale solid-state schemes are being implemented in a range of materials. Nanofabricated quantum dots can be made in designer configurations, with established technology for controlling interactions and for reading out results. Epitaxial quantum dots can be grown in vertical arrays in semiconductors, and ultrafast optical techniques are available for controlling and measuring their excitations. Single-walled carbon nanotubes can be used for molecular self-assembly of endohedral fullerenes, which can embody quantum information in the electron spin. The challenges of individual addressing in such tiny structures could rapidly become intractable with increasing numbers of qubits, but these schemes are amenable to global addressing methods for computation.

Fermi-surface topology and the effects of intrinsic disorder in a class of charge-transfer salts containing magnetic ions, \beta''-(BEDT-TTF)_4[(H_3O)M(C_2O_4)_3]Y

(2003)

Authors:

AI Coldea, AF Bangura, J Singleton, A Ardavan, A Akutsu-Sato, H Akutsu, SS Turner, P Day

Angle-dependence of the magnetotransport and Anderson localization in a pressure-induced organic superconductor

SYNTHETIC MET 137:1-3 (2003) 1287-1288

Authors:

P Goddard, SW Tozer, J Singleton, A Ardavan, A Bangura, M Kurmoo

Abstract:

The conducting properties of the pressure-induced, layered organic superconductor (BEDT-TTF)(3)Cl-2 . 2H(2)O have been studied at 13.5 and 14.0 kbar using low temperatures, high magnetic fields and two-axis rotation. The observed negative magnetoresistance at 13.5 kbar can be explained by considering Anderson localization within the layers. Further application of pressure destroys the effects of localization.

Magnetotransport measurements on beta ''-(BEDT-TTF)(4)[(H3O)Ga3+(C2O4)(3)](center dot) C6N5NO2

SYNTHETIC MET 137:1-3 (2003) 1313-1314

Authors:

AF Bangura, AI Coldea, J Singleton, A Ardavan, AK Klehe, A Akutsu-Sato, H Akutsu, SS Turner, P Day

Abstract:

Transport measurements have been carried out on single crystals of the charge transfer salt beta"-(BEDT-TTF)(4)[(H3O) Ga3+ (C2O4)(3)]. C6H5NO2, using magnetic fields of up to 33 T and temperatures down to 0.55 K. The material is found to be superconducting with T. 7.5 K and an in-plane critical field B-c2 greater than or equal to 33 T, and to exhibit Shubnikov-de Haas (SdH) oscillations. The temperature and angle dependence of the Shubnikov-de Haas oscillations and the upper critical field are reported, allowing information about the anisotropy of the upper critical field, effective mass m*, and the Fermi-surface (FS) of the material to be deduced.

Magnetotransport measurements on β"-(BEDT-TTF)4[(H3O)Ga3+(C2 O4)3]. C6H5NO2

Synthetic Metals 137:1-3 (2003) 1313-1314

Authors:

AF Bangura, AI Coldea, J Singleton, A Ardavan, AK Klehe, A Akutsu-Sato, H Akutsu, SS Turner, P Day

Abstract:

Transport measurements have been carried out on single crystals of the charge transfer salt β″-(BEDT-TTF)4[(H3O)Ga³⁺(C2 O4)3]. C6H5NO2, using magnetic fields of up to 33 T and temperatures down to 0.55 K. The material is found to be superconducting with Tc ≈ 7.5 K and an in-plane critical field Bc2 ≥ 33 T, and to exhibit Shubnikov-de Haas (SdH) oscillations. The temperature and angle dependence of the Shubnikov-de Haas oscillations and the upper critical field are reported, allowing information about the anisotropy of the upper critical field, effective mass m*, and the Fermi-surface (FS) of the material to be deduced.

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