Transporte de electrones en anillos cuánticos de confinamiento variable
JJ. Gonzalez Armesto y L. Diago Cisneros
Facultad de Física de la Universidad de la Habana, La Habana, Cuba. e-mail: jjgonzalez@ñsica.uh.cu; ldiago@física.uh.cu
Received 8 June 2015; ]]> accepted 3 November 2015
Resumen
Se analiza las influencias que tiene sobre el transporte de electrones en un anillo cuántico de Aharonov-Bohm el modelar las entradas en forma de constricciones cuadráticas tipo contacto de punto cu谩ntico (QPCs), con presencia de interacción espín-orbita tipo Rashba. Se obtienen comportamientos ondulatorios de la conductancia consistentes con las oscilaciones de Aharonov-Bohm (AB) y Aharonov-Casher (AC) y se estudian las modificaciones de las mismas ante variaciones de la opacidad de los QPCs. Se reproducen comportamientos anteriormente analizados y se aprecian marcadas diferencias en los períodos de los arm贸nicos de la conductancia con respecto a trabajos anteriores del tema. Adem谩s, se discuten los formalismos te贸ricos, obteniendose toda la fenomenología del anillo como soluci贸n directa de la ecuaci贸n de Pauli para un anillo unidimensional. Se plantean algunos de los posibles efectos de las asimetrías en los confinamientos en los QPCs sobre los comportamientos antes discutidos.
Palabras clave: Espintr贸nica; efecto AB; interferencia cu谩ntica.
Abstract
Influences on electronic transport in a Aharonov-Bohm quantum ring of modeling the entrances as quadratic quantum point contact (QPC) are taken into account in the presence of Rashba spin-orbit interaction. Oscillations in the conductance are obtained, consistent with Aharonov-Bohm and Aharonov-Casher oscillations and their behaviour is analyzed as the opacity in the quantum point contacts changes. We are able to reproduce previous phenomena and obtain differences with other results for the periods between the conductance harmonics. We discuss the theoretical formalism, and besides have studied all the physics of interest by solving the one-dimensional Pauli equation for the ring solely. Some possible effects of the asymmetrical confinements in the QPCs are studied as well as their influence on the previous results.
Keywords: Spintronics; AB effect; quantum interference.
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