Quantum rings with tunnel barriers in a threading magnetic field: Spectra, persistent current and ballistic conductance

Distribution of persistent currents in a multi-arm mesoscopic ring

“…These currents are periodic in φ exhibiting φ 0 fluxquantum periodicity. The presented current-flux characteristics for this single-channel ring exactly match with the previous theoretical studies where persistent currents have been calculated by other approaches [1][2][3][4][5][6][7][8][9][10].…”

“…It is noticed that the responses of the individual branches are quite different from each other, especially, a significant change in amplitude takes place among the currents I U , I M and I L . By adding these three currents we get the net current (I T ) for the entire ring and it becomes exactly identical to the current determined from the other conventional methods available in the literature [1][2][3][4][5][6][7][8][9][10]. This emphasizes the current conservation relation I T = I U + I M + I L .…”

“…The appearance of discrete energy levels and large phase coherence length allow a non-decaying current in presence of an AB flux φ. Following the pioneering work of Büttiker et al [1], various efforts have been made to explore the basic mechanisms of persistent current in mesoscopic rings and cylinders [2][3][4][5][6][7][8][9][10]. Later, the existence of non-decaying current in these systems has also been verified through some nice experiments [11][12][13][14].…”

Magneto-Transport in Closed and Open Mesoscopic Loop Structures: A Review

“…The correlations in the energy spectrum governs that the ratio of the total and single-level currents is proportional to √ M 40 . Similar to persistent current in such isolated closed loop geometries, the non-decaying charge current is also observed in open loop systems [43][44][45][46][47][48][49][50][51] , where rings/cylinders are coupled to source and drain electrodes. In 1985, Büttiker has introduced a conceptually simple and elegant approach 43 to investigate the effect of an electron reservoir on persistent current in a loop penetrated by a magnetic flux.…”

Carbon nanotube in a threading magnetic field: Conductance oscillations persistent current and magnetization

“…Since the early 1980s when the emergence of persistent current in metallic systems with a ring geometry has been explored [40], a huge effort has been devoted to the study and the realization of devices with a circular shape at the nanometric scale. Several experiments [41][42][43][44][45][46] have been performed in both ring and cylindrical geometries with the aim of measuring persistent current and many theoretical works [47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] were dedicated to the study of this topic. In a many-body system of N particles, the persistent current can be calculated starting from the ground state energy E 0 for a particular filling at absolute zero temperature (T ¼ 0 K).…”