Tunneling Spectroscopy of a Two-Dimensionally Periodic Electron System

Zolleis, K. R.; Ford, C. J. B.; Kardynał, Beata; Ritchie, D. A.; Linfield, Edmund H.; Rose, P. D.; Jones, G. A. C.

doi:10.1103/physrevlett.89.146803

Cited by 3 publications

(4 citation statements)

References 26 publications

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“…In general, all these phenomena can be induced by the manipulation of quantum interference effects [31,32] using different dot sizes, geometries, confinement potential shapes and the variation of the electronic density and magnetic field intensity [33]. In this work we discuss, for the exclusively quantum low energy regime, the closed-open transition of an OQD as a function of the applied magnetic field by varying the QPC width that connects the quantum dot (QD) with the leads.…”

Section: Introductionmentioning

confidence: 99%

Magneto-conductance fingerprints of purely quantum states in the open quantum dot limit

Mendoza

Ujevic

2012

J. Phys.: Condens. Matter

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We present quantum magneto-conductance simulations, at the quantum low energy condition, to study the open quantum dot limit. The longitudinal conductance G(E,B) of spinless and non-interacting electrons is mapped as a function of the magnetic field B and the energy E of the electrons. The quantum dot linked to the semi-infinite leads is tuned by quantum point contacts of variable width w. We analyze the transition from a quantum wire to an open quantum dot and then to an effective closed system. The transition, as a function of w, occurs in the following sequence: evolution of quasi-Landau levels to Fano resonances and quasi-bound states between the quasi-Landau levels, followed by the formation of crossings that evolve to anti-crossings inside the quasi-Landau level region. After that, Fano resonances are created between the quasi-Landau states with the final generation of resonant tunneling peaks. By comparing the G(E,B) maps, we identify the closed and open-like limits of the system as a function of the applied magnetic field. These results were used to build quantum openness diagrams G(w,B). Also, these maps allow us to determine the w-limit value from which we can qualitatively relate the closed system properties to the open one. The above analysis can be used to identify single spinless particle effects in experimental measurements of the open quantum dot limit.

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Section: Introductionmentioning

confidence: 99%

Magneto-conductance fingerprints of purely quantum states in the open quantum dot limit

Mendoza

Ujevic

2012

J. Phys.: Condens. Matter

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“…The investigations in the field of magnetoelectronic transport in twodimensional antidot lattice systems ͑ballistic͒ are mostly related to one of the following topics: ͑i͒ studies on the quantum-classical limit and its relation to quantum chaos, [16][17][18][19] which is mainly focused on the study of electrons dynamics associated with classical orbits or scars wave functions, [20][21][22] and ͑ii͒ studies about the manipulation of the electronic-transport regimes, 6,[23][24][25] such as electronic localization effects, conductor-insulator transition, surface states, and quantum Hall effect. In general, these phenomena can be induced by the manipulation of quantum interference effects using different lattice geometries, shapes, sizes, and number of the antidots, or due to the intensity variation in the applied external fields.…”

Section: Introductionmentioning

confidence: 99%

Fingerprints of transverse and longitudinal coupling between induced open quantum dots in the longitudinal magnetoconductance through antidot lattices

Ujevic

Mendoza

2010

Phys. Rev. B

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We propose numerical simulations of longitudinal magnetoconductance through a finite antidot lattice located inside an open quantum dot with a magnetic field applied perpendicular to the plane. The system is connected to reservoirs using quantum point contacts. We discuss the relationship between the longitudinal magnetoconductance and the generation of transversal couplings between the induced open quantum dots in the system. The system presents longitudinal magnetoconductance maps with crossovers ͑between transversal bands͒ and closings ͑longitudinal decoupling͒ of fundamental quantum states related to the open quantum dots induced by the antidot lattice. A relationship is observed between the distribution of antidots and the formed conductance bands, allowing a systematic follow up of the bands as a function of the applied magnetic field and quantum point-contact width. We observed a high conductance intensity ͓between n and ͑n +1͒ quantum of conductance, n =1,2,. . .͔ in the regions of crossover and closing of states. This suggests transversal couplings between the induced open quantum dots of the system that can be modulated by varying both the antidots potential and the quantum point-contact width. A new continuous channel ͑not expected͒ is induced by the variation in the contact width and generate Fano resonances in the conductance. These resonances can be manipulated by the applied magnetic field.

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“…In contrast, for a TLL, there should be two features, for spin and charge, instead of one for a non-interacting 1D subband. [6,7] We have previously used ion-beam lithography to make separate contact to two such layers of electrons, for investigating arrays of 1D wires [8] and antidots [9], but here we adopt a simpler technique that uses just surface gates and allows measurements even when the last 1D subband is nearly depleted. With this technique, we probe the single-particle spectrum of the 1D system down to single subband.…”

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confidence: 99%

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Probing e–e interactions in a periodic array of GaAs quantum wires

Jompol

Ford

Farrer

et al. 2008

Physica E: Low-dimensional Systems and Nanostructures

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We present the results of non-linear tunnelling spectroscopy between an array of independent quantum wires and an adjacent two-dimensional electron gas (2DEG) in a double-quantum-well structure. The two layers are separately contacted using a surface-gate scheme, and the wires are all very regular, with dimensions chosen carefully so that there is minimal modulation of the 2DEG by the gates defining the wires. We have mapped the dispersion spectrum of the 1D wires down to the depletion of the last 1D subband by measuring the conductance G as a function of the in-plane magnetic field B, the interlayer bias V dc and the wire gate voltage. There is a strong suppression of tunnelling at zero bias, with temperature and dc-bias dependences consistent with power laws, as expected for a Tomonaga-Luttinger Liquid caused by electron-electron interactions in the wires. In addition, the current peaks fit the free-electron model quite well, but with just one 1D subband there is extra structure that may indicate interactions. adjacent low-disorder 2D layer depends on the overlap between the spectral functions of the two systems, which is varied by using an in-plane magnetic field B perpendicular to the wires to offset the two in k-space; a bias V dc between the layers is used to investigate the energy dependence. In a non-interacting system, peaks in the conductance G follow the 1D and 2D subbands. In contrast, for a TLL, there should be two features, for spin and charge, instead of one for a non-interacting 1D subband. [6,7] We have previously used ion-beam lithography to make separate contact to two such layers of electrons, for investigating arrays of 1D wires [8] and antidots [9], but here we adopt a simpler technique that uses just

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Tunneling Spectroscopy of a Two-Dimensionally Periodic Electron System

Cited by 3 publications

References 26 publications

Magneto-conductance fingerprints of purely quantum states in the open quantum dot limit

Magneto-conductance fingerprints of purely quantum states in the open quantum dot limit

Fingerprints of transverse and longitudinal coupling between induced open quantum dots in the longitudinal magnetoconductance through antidot lattices

Probing e–e interactions in a periodic array of GaAs quantum wires

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