Autor: Weymann, I. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Current Suppression in Transport Through Triple Quantum Dots Coupled to Ferromagnetic Leads
Autorzy:: Wrześniewski, K.
Weymann, I.
Powiązania:: https://bibliotekanauki.pl/articles/1386617.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.23.-b
73.21.La
85.75.-d
Opis:: We consider transport through triple quantum dot system in a triangular geometry weakly coupled to external ferromagnetic leads. The real-time diagrammatic technique in the lowest order perturbation theory is used to calculate the current and Fano factor in the parallel and antiparallel magnetic configuration of the system as well as the resulting tunnel magnetoresistance (TMR). We focus on the transport regime where the current is suppressed and show that it can lead to negative differential conductance and large super-Poissonian shot noise, which are present in both magnetic configurations. Furthermore, we show that for voltages where the system is trapped in a one-particle dark state the TMR becomes suppressed, while for two-particle blockade, the TMR is much enhanced.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 460-462
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Influence of Magnetic Field on Dark States in Transport through Triple Quantum Dots
Autorzy:: Wrześniewski, K.
Weymann, I.
Powiązania:: https://bibliotekanauki.pl/articles/1032454.pdf
Data publikacji:: 2017-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.23.-b
73.21.La
Opis:: We theoretically study the electronic transport through a triple quantum dot system in triangular geometry weakly coupled to external metallic leads. By means of the real-time diagrammatic technique, the current and Fano factor are calculated in the lowest order of perturbation theory. The device parameters are tuned to such transport regime, in which coherent population trapping of electrons in quantum dots due to the formation of dark states occurs. The presence of such states greatly influences transport properties leading to a strong current blockade and enhanced, super-Poissonian shot noise. We consider both one- and two-electron dark states and examine the influence of magnetic field on coherent trapping in aforementioned states. When the system is in one-electron dark state, we observe a small shift of the blockade's region, whereas in the case of two-electron dark state, we show that strong magnetic field can lift the current blockade completely.
Źródło:: Acta Physica Polonica A; 2017, 132, 1; 108-111
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Andreev Transport through a Magnetic Molecule Weakly Coupled to Ferromagnetic Leads
Autorzy:: Pawlicki, F.
Weymann, I.
Powiązania:: https://bibliotekanauki.pl/articles/1030385.pdf
Data publikacji:: 2018-03
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.23.-b
74.45.+c
75.50.Xx
Opis:: The Andreev transport through a single molecular magnet coupled to two external ferromagnetic leads and one superconducting electrode is studied theoretically by means of the real-time diagrammatic technique. The calculations are performed by including the sequential tunneling processes between the molecule and ferromagnetic leads, while the coupling to superconductor can be arbitrary. We analyze the dependence of the Andreev current and tunnel magnetoresistance on various intrinsic parameters of the molecule. The superconducting proximity effect results in the formation of molecular Andreev bound states. We show that the transport behavior depends greatly on the type of internal exchange interaction of the molecule, which can lead to corresponding sign changes of the tunnel magnetoresistance of the device.
Źródło:: Acta Physica Polonica A; 2018, 133, 3; 594-596
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Andreev Transport in Double Quantum Dot Cooper Pair Splitters in the Presence of External Magnetic Field
Autorzy:: Trocha, P.
Weymann, I.
Powiązania:: https://bibliotekanauki.pl/articles/1386830.pdf
Data publikacji:: 2015-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.23.-b
73.21.La
74.45.+c
Opis:: The effect of external magnetic field on the transport properties of double quantum dots coupled to normal and superconducting leads is studied by means of the real-time diagrammatic technique in the sequential tunneling regime. This device works as a gate-controlled Cooper pair splitter. We focus on the transport regime where the current is blocked due to the spin triplet blockade. It is shown that external magnetic field can modify the Andreev current and differential conductance. In particular, magnetic field can suppress the negative differential conductance associated with the triplet blockade.
Źródło:: Acta Physica Polonica A; 2015, 127, 2; 502-504
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Andreev Conductance through a Quantum Dot Strongly Coupled to Ferromagnetic and Superconducting Leads
Autorzy:: Wójcik, K.P.
Weymann, I.
Powiązania:: https://bibliotekanauki.pl/articles/1032390.pdf
Data publikacji:: 2017-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.23.-b
72.15.Qm
74.45.+c
72.25.-b
Opis:: We analyze the Andreev conductance through a quantum dot strongly coupled to one ferromagnetic and one superconducting lead. The transmission due to the Andreev reflection is obtained from the numerical renormalization group method. We show that at low temperatures, depending on the dot level position, the Andreev conductance exhibits a peak at zero bias due to the Kondo effect, which can be split by the exchange field due to spin-dependent coupling to ferromagnetic lead.
Źródło:: Acta Physica Polonica A; 2017, 132, 1; 143-145
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 6.

Tytuł:: Signatures of Transverse Magnetic Anisotropy in Transport through a Large-Spin Molecule in the Kondo Regime
Autorzy:: Misiorny, M.
Weymann, I.
Barnaś, J.
Powiązania:: https://bibliotekanauki.pl/articles/1402574.pdf
Data publikacji:: 2015-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 72.10.Fk
72.25.-b
73.23.-b
75.50.Xx
Opis:: The effect of transverse magnetic anisotropy on spin-dependent transport through a large-spin molecule strongly tunnel-coupled to ferromagnetic electrodes is analyzed theoretically. In particular, we investigate whether it is possible to observe in transport signatures of oscillations of the ground-state doublet splitting due to the application of an external magnetic field along the molecule's hard axis. We show that magnetic field leads to revivals of the Kondo effect, with the Kondo temperature depending on the magnetic configuration of the device.
Źródło:: Acta Physica Polonica A; 2015, 128, 2; 200-203
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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