Eur. Phys. J. B 80, 105-114 (2011)
https://doi.org/10.1140/epjb/e2011-10931-6

Logical XOR gate response in a quantum interferometer: A spin dependent transport

¹ Theoretical Condensed Matter Physics Division, Saha Institute of Nuclear Physics, Sector-I, Block-AF, Bidhannagar, 700064 Kolkata, India
² Department of Physics, Narasinha Dutt College, 129 Belilious Road, 711101 Howrah, India

Corresponding author: ^a santanu.maiti@saha.ac.in

Received: 28 November 2010
Revised: 19 January 2011
Published online: 1 March 2011

Abstract

We examine spin dependent transport in a quantum interferometer composed of magnetic atomic sites based on transfer matrix formalism. The interferometer, threaded by a magnetic flux ϕ, is symmetrically attached to two semi-infinite one-dimensional (1D) non-magnetic electrodes, namely, source and drain. A simple tight-binding model is used to describe the bridge system, and, here we address numerically the conductance-energy and current-voltage characteristics as functions of the interferometer-to-electrode coupling strength, magnetic flux and the orientation of local the magnetic moments associated with each atomic site. Quite interestingly it is observed that, for ϕ = ϕ₀/2 (ϕ₀ = ch/e, the elementary flux-quantum) a logical XOR gate like response is observed, depending on the orientation of the local magnetic moments associated with the magnetic atoms in the upper and lower arms of the interferometer, and it can be changed by an externally applied gate magnetic field. This aspect may be utilized in designing a spin based electronic logic gate.