We experimentally demonstrate the validity of nonequilibrium fluctuation relations by using a quantum coherent conductor. In equilibrium fluctuation-dissipation relation leads to correlation between current and noise at conductor, namely, Johnson-Nyquist relation. When conductor is voltage biased so that nonlinear regime entered, theorem has predicted similar relations, which hold true even when Onsager-Casmir are broken in magnetic fields. Our experiments qualitatively validate predictions...

Epitaxial thin films of ordered double-perovskite La2NiMnO6 were deposited on SrTiO3, (LaAlO3)0.3–(Sr2AlTaO6)0.7, and LaAlO3 substrates by a pulsed-laser deposition method. A rock-salt-type ordering for Ni2+ Mn4+ ions was confirmed through structural magnetic measurements. Despite the difference in heteroepitaxial constraints crystal structure, properties quite similar to each other also those bulk La2NiMnO6.

Epitaxial thin films of Bi2NiMnO6 were synthesized on SrTiO3 substrates by pulsed laser deposition. The resulting film had the rock-salt-type arrangement Ni2+ and Mn4+ ions in a double-perovskite unit cell. clearly showed multiferroic properties, both ferromagnetic behavior with Curie temperature about 100K ferroelectric saturated polarization 5μC∕cm2.

We investigate intrinsic and extrinsic decay of edge magnetoplasmons (EMPs) in graphene quantum Hall (QH) systems by high-frequency electronic measurements. From EMP resonances disk shaped graphene, we show that the dispersion relation EMPs is nonlinear due to interactions, giving rise wavepacket. also identify dissipation mechanisms interaction with localized states bulk from time wavepackets. indicate that, owing unique linear gapless band structure, can be lower than GaAs systems.

Shot noise, originating from the discrete nature of electric charge, is generated by scattering processes. Shot-noise measurements have revealed microscopic charge dynamics in various quantum transport phenomena. In particular, beyond single-particle picture, such proved to be powerful ways investigate electron correlation liquids. Here, we review recent progress shot-noise mesoscopic physics. This summarizes basics theory based on Landauer-Büttiker formalism, measurement techniques used...

Plasmons, which are collective charge oscillations, offer the potential to use optical signals in nano-scale electric circuits. Recently, plasmonics using graphene have attracted interest, particularly because of tunable plasmon frequency through carrier density $n$. However, $n$ dependence velocity is weak ($\propto n^{1/4}$) and it difficult tune over orders magnitude. Here, we demonstrate that plasmons can be changed two magnitude by applying a magnetic field $B$ presence/absence gate; at...

Abstract Electron correlation in a quantum many-body state appears as peculiar scattering behaviour at its boundary, symbolic of which is Andreev reflection metal-superconductor interface. Despite being fundamental nature, dictated by the charge conservation law, however, process has had no analogues outside realm superconductivity so far. Here, we report observation an Andreev-like originating from topological effect instead superconductivity. A narrow junction between fractional and...

Mesoscopic systems provide us a unique experimental stage to address non-equilibrium quantum statistical physics. By using simple tunneling model, we describe the electron exchange process via coherent conductor between two reservoirs, which yields fluctuation theorem (FT) in mesoscopic transport. We experimentally show that such treatment is semi-quantitatively validated current and noise measurement an Aharonov-Bohm ring. The proof of microreversibility assumed derivation FT presented.

We report experimental and theoretical studies of edge magnetoplasmon (EMP) transport in quantum Hall (QH) devices. develop a model that allows us to calculate the coefficients EMPs QH devices with various geometries. In our model, system is described as chiral distributed-element (CDE) circuit, where effects Coulomb interaction are represented by an electrochemical capacitance distributed along unidirectional transmission lines. measure EMP through single- coupled-edge channels, point...

We describe high-frequency admittance measurements up to 3 GHz on a quantum point contact in Hall regime. When the excitation frequency is so high that wavelength of edge magnetoplasmons comparable size system, phase developing along channels must be considered when analyzing electrochemical capacitance admittance. The result cannot accounted for by local near but instead needs understood considering distributed within sample as whole. This implies all electrons device are interacting...

A Tomonaga-Luttinger (TL) liquid is known as an integrable system, in which a nonequilibrium many-body state survives without relaxing to thermalized state. This intriguing characteristic tested experimentally copropagating quantum Hall edge channels at bulk filling factor ν=2. The unidirectional transport allows us investigate the time evolution by measuring spatial of electronic states. initial prepared with biased point contact, and its measured quantum-dot energy spectrometer. We find...

In interacting one-dimensional (1D) systems, the quasi-particle picture in Fermi-liquid theory cannot successfully describe low-energy physics. Instead, electron dynamics one dimension can be described as collective excitations, i.e., charge- and/or spin-density waves, which are elementary excitations a Tomonaga-Luttinger (TL) liquid. Integer quantum Hall (QH) edge channels, chiral 1D states formed along periphery of integer QH provide unique opportunity for studying TL-liquid When channels...

Abstract Fractionalization is a phenomenon where an elementary excitation partitions into several pieces. This picture explains non-trivial transport through junction of one-dimensional edge channels defined by topologically distinct quantum Hall states, for example, hole-conjugate state at Landau-level filling factor ν = 2/3. Here we employ time-resolved scheme to identify fractionalization process; injection charge q from non-interaction region interacting and scattering results in the...

Hot electron transport in a quantum Hall edge channel of an AlGaAs/GaAs heterostructure is studied by investigating the energy distribution function channel. Ballistic hot-electron transport, its optical-phonon replicas, weak electron-electron scattering, and electron-hole excitation Fermi sea are clearly identified spectra. The authors find that scattering significantly suppressed with increasing well above energy. This can be understood as deriving from Coulomb potential at larger...

A new topological device architecture provides clear evidence of disorder-dominated couplings among counterpropagating edge channels, a key insight for quantum technologies that rely on channel manipulation.

We have experimentally identified fractional quasiparticle creation in a tunneling process through local quantum Hall (FQH) state. The FQH state is prepared low-density region near point contact (QPC) an integer (IQH) system. Shot-noise measurements reveal clear transition from elementary-charge at low bias to fractional-charge high bias. shot noise proportional T1(1 ? T1) over wide range of T1, where T1 the transmission probability IQH edge channel. This binomial distribution indicates that...

Charge equilibration between quantum-Hall edge states can be studied to reveal geometric structure of channels not only in the integer quantum Hall (IQH) regime but also fractional (FQH) particularly for hole-conjugate states. Here we report on a systematic study charge both IQH and FQH regimes by using generalized bar, which state is nested another with different Landau filling factors. This provides feasible way evaluate various conditions even presence scattering bulk region. The validity...