Lee, Minchul, Choi, Mahn-Soo, Lopez, Rosa, Aguado, Ramon, Martinek, Jan, Zitko, Rok
We study a series-coupled double quantum dot in the Kondo regime modeled by the two-impurity Anderson model and find a new conduction-band mediated superexchange interaction that competes with Kondo...
Frequency-Dependent Current Noise through Quantum-Dot Spin Valves (2006)
Braun, Matthias, König, Jürgen, Martinek, Jan
We study frequency-dependent current noise through a single-level quantum dot connected to ferromagnetic leads with non-collinear magnetization. We propose to use the frequency-dependent Fano factor...
Manipulating Single Spins in Quantum Dots Coupled to Ferromagnetic Leads (2005)
Braun, Matthias, König, Jürgen, Martinek, Jan
We discuss the possibility to generate, manipulate, and probe single spins in single-level quantum dots coupled to ferromagnetic leads. The spin-polarized currents flowing between dot and leads lead...
Weymann, Ireneusz, König, Jürgen, Martinek, Jan, Barnas, Józef, Schön, Gerd
We study electronic transport through quantum dots weakly coupled to ferromagnetic leads with collinear magnetization directions. Tunneling contributions of first and second order in the...
Nonequilibrium Kondo Effect in a Quantum Dot Coupled to Ferromagnetic Leads (2005)
Utsumi, Yasuhiro, Martinek, Jan, Schön, Gerd, Imamura, Hiroshi, Maekawa, Sadamichi
We study the Kondo effect in the electron transport through a quantum dot coupled to ferromagnetic leads, using a real-time diagrammatic technique which provides a systematic description of the...
Zero-bias anomaly in cotunneling transport through quantum-dot spin valves (2004)
Weymann, Ireneusz, Barnaś, Józef, König, Jürgen, Martinek, Jan, Schön, Gerd
We predict a new zero-bias anomaly in the differential conductance through a quantum dot coupled to two ferromagnetic leads with antiparallel magnetization. The anomaly differs in origin and...
Spin current through a tunnel junction (2004)
Braun, Matthias, König, Jürgen, Martinek, Jan
We derive an expression for the spin-current through a tunnel barrier in terms of many-body Green's functions. The spin current has two contributions. One can be associated with angular-momentum...
Hanle Effect in Transport through Quantum Dots Coupled to Ferromagnetic Leads (2004)
Braun, Matthias, König, Jürgen, Martinek, Jan
We suggest a series of transport experiments on spin precession in quantum dots coupled to one or two ferromagnetic leads. Dot spin states are created by spin injection and analyzed via the linear...
König, Jürgen, Martinek, Jan, Barnas, Jozef, Schön, Gerd
Spintronics devices rely on spin-dependent transport behavior evoked by the presence of spin-polarized electrons. Transport through nanostructures, on the other hand, is dominated by strong Coulomb...
Theory of Transport through Quantum-Dot Spin Valves in the Weak-Coupling Regime (2004)
Braun, Matthias, König, Jürgen, Martinek, Jan
We develop a theory of electron transport through quantum dots that are weakly coupled to ferromagnetic leads. The theory covers both the linear and nonlinear transport regime, takes non-collinear...
Indirect Exchange Interaction between two Quantum Dots in an Aharonov-Bohm Ring (2003)
Utsumi, Yasuhiro, Martinek, Jan, Bruno, Patrick, Imamura, Hiroshi
We investigate the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between two spins located at two quantum dots embedded in an Aharonov-Bohm (AB) ring. In such a system the RKKY interaction, which...
Interaction-driven spin precession in quantum-dot spin valves (2002)
We analyze spin-dependent transport through spin valves composed of an interacting quantum dot coupled to two ferromagnetic leads. The spin on the quantum dot and the linear conductance as a function...
Nonequilibrium spin fluctuations in single-electron transistors (2002)
Martinek, Jan, Barnas, Józef, Schön, Gerd, Takahashi, Saburo, Maekawa, Sadamichi
We show that nonequilibrium spin fluctuations significantly influence the electronic transport in a single-electron transistor, when the spin relaxation on the island is slow compared to other...
Spin accumulation in ferromagnetic single-electron transistors in the cotunneling regime (2002)
Martinek, Jan, Barnas, Józef, Maekawa, Sadamichi, Schoeller, Herbert, Schön, Gerd
We propose a new method of direct detection of spin accumulation, which overcomes problems of previous measurement schemes. A spin dependent current in a single-electron transistor with ferromagnetic...