相关论文: Designing a highly efficient graphene quantum spin…

We analyze the heat current traversing a quantum dot sandwiched between a ferromagnetic and a superconducting electrode. The heat flow generated in response to a voltage bias presents rectification as a function of the gate potential…

Spin pumping consists in the injection of spin currents into a non-magnetic material due to the precession of an adjacent ferromagnet. In addition to the pumping of spin the precession always leads to pumping of heat, but in the presence of…

A proposal to detect the purported canted antiferromagnet order for the $\nu=0$ quantum Hall state of graphene based on a two-terminal spin transport setup is theoretically discussed. In the presence of a magnetic field normal to the…

Performance of nano- and micro-scale heat engines can be improved with a help from quantum mechanical phenomena. Recently, heat reservoirs with quantum coherence have been proposed to enhance engine performance beyond the Carnot limit even…

Spintronics---the all-electrical control of the electron spin for quantum or classical information storage and processing---is one of the most promising applications of the two-dimensional material graphene. Although pristine graphene has…

While microscopic laws of physics are invariant under the reversal of the arrow of time, the transport of energy and information in most devices is an irreversible process. It is this irreversibility that leads to intrinsic dissipations in…

Hybrid quantum systems can often be described in terms of polaritons. These are quasiparticles formed of superpositions of their constituents, with relative weights depending on some control parameter in their interaction. In many cases,…

We report fabrication of graphene devices in a Corbino geometry consisting of concentric circular electrodes with no physical edge connecting the inner and outer electrodes. High device mobility is realized using boron nitride encapsulation…

We propose an autonomous quantum heat engine based on the thermally driven oscillation of a single electron shuttle. The electronic degree of freedom of this device acts as an internal dynamical controller which switches the interaction of…

The presence of edge channels in the quantum Hall regime leads to dissipationless charge transport over long distances. When graphene is interfaced with a magnetic material, the exchange interaction lifts the Landau levels spin degeneracy.…

In this work, we propose a path integral-inspired formalism for computing the quantum thermal expectation values of spin systems, when subject to magnetic fields that can be time-dependent and can accommodate the presence of Heisenberg…

Graphene - a single atomic layer of graphite - is a recently-found two-dimensional form of carbon, which exhibits high crystal quality and ballistic electron transport at room temperature. Soft magnetic NiFe electrodes have been used to…

We study electronic transport in graphene/ferromagnetic insulator hybrid devices. The system comprises an armchair graphene nanoribbon with a lens-shaped EuO ferromagnetic insulator layer deposited on top of it. When the device supports a…

We report a theoretical investigation of quantized spin-Hall conductance fluctuation of graphene devices in the diffusive regime. Two graphene models that exhibit quantized spin-Hall effect (QSHE) are analyzed. Model-I is with unitary…

Double-gated graphene devices provide an important platform for understanding electrical and optical properties of graphene. Here we present transport measurements of single layer, bilayer and trilayer graphene devices with suspended top…

Conventional continuous quantum heat engines with incoherent heat transfer perform poorly as they exploit two-body interactions between the system and hot or cold baths, thus having limited capability to outperform their classical…

We report on the injection of quantized pure spin current into quantum conductors. In particular, we propose an on demand single spin source generated by periodically varying the gate voltages of two quantum dots that are connected to a two…

We develop a hydrodynamic theory of charge and heat currents induced by traveling waves, such as surface acoustic waves, in graphene devices near charge neutrality. The currents depend on the intrinsic conductivity and viscosity of the…

We propose a spin-star network, where a central spin-$1/2$ is coupled with XXZ interaction to $N$ outer spin-$1/2$ particles, as a quantum fuel. If the network is in thermal equilibrium with a cold bath, the central spin can have an…

We present a theory of graphene quantum rings designed to produce degenerate shells of single particle states close to the Fermi level. We show that populating these shells with carriers using a gate leads to correlated ground states with…