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Article
Photocurrent-driven transient symmetry breaking in the Weyl semimetal TaAs
Symmetry plays a central role in conventional and topological phases of matter, making the ability to optically drive symmetry changes a critical step in develo** future technologies that rely on such contro...
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Article
Open AccessTemperature-tunable Fano resonance induced by strong coupling between Weyl fermions and phonons in TaAs
Strong coupling between discrete phonon and continuous electron–hole pair excitations can induce a pronounced asymmetry in the phonon line shape, known as the Fano resonance. This effect has been observed in v...
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Article
Using ultrashort optical pulses to couple ferroelectric and ferromagnetic order in an oxide heterostructure
A new approach to all-optical detection and control of the coupling between electric and magnetic order on ultrafast timescales is achieved using time-resolved second-harmonic generation (SHG) to study a ferro...
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Article
Open AccessProbing the Interplay between Quantum Charge Fluctuations and Magnetic Ordering in LuFe2O4
The mechanisms producing strong coupling between electric and magnetic order in multiferroics are not always well understood, since their microscopic origins can be quite different. Hence, gaining a deeper und...
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Chapter and Conference Paper
Ultrafast Carrier Dynamics in Semiconductor Nanowires
Ultrafast wavelength-tunable optical measurements on semiconductor nanowires allow us to independently probe the dynamics of electrons, holes, and defect states. These investigations reveal the influence of tw...
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Chapter
Numerical Solution of the Holstein Polaron Problem
Noninteracting itinerant electrons in a solid occupy Bloch one-electron states. Phonons are collective vibrational excitations of the crystal lattice. The basic electron-phonon (EP) interaction process is the ...
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Article
Jahn–Teller and the Dynamics of Polaron Formation
We discuss a powerful algorithm for calculating static and dynamic properties of electron–phonon coupled systems with dynamic quantum phonons. The difference between Jahn–Teller polarons present in certain tra...
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Chapter and Conference Paper
The Dynamics of Inelastic Quantum Tunneling
We describe how to obtain a numerically exact solution for an electron tunneling through a molecule or nanodot coupled to arbitrary phonon and spin degrees of freedom. Fully quantum and semiclassical tunneling...
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Chapter and Conference Paper
Ultrafast THz conductivity dynamics: spinlattice relaxation in colossal magnetoresistive oxides
Ultrafast measurements of optically induced changes in the conductivity (0.4-1.0 THz) of La0.7M0.3MnO3 films (M = Ca, Sr) from -10K to -0.9Tc reveal a spin-lattice relaxation that follows the temperature dependen...
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Article
Mobile Bipolaron—Strong Coupling Approach
We explore the properties of the bipolaron in a 1D Holstein–Hubbard model with dynamical quantum phonons. We apply strong coupling theory to investigate the intersite bipolaron. We investigate the influence of...
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Article
The Polaron: Ground State, Excited States, and Far from Equilibrium
We describe a variational approach for solving the Holstein polaron model with dynamical quantum phonons on an infinite lattice. The method is simple, fast, extremely accurate, and gives ground and excited sta...
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Article
Isotopic Shifts in a Polaronic System
The effect of isotopic substitution in a model polaronic system is presented.We use a three-site many body electron–phonon model which includeselectronic correlations and electron–phonon interactions, showing ...
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Article
Materials Development for Thermomagnetic Cooling
We review thermoelectric effects in a magnetic field at a phenomenological level. The measurement problem is discussed in detail, and results are presented based on the time-dependent voltages developed by the...
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Chapter and Conference Paper
Nonequilibrium Superconductivity and Quasiparticle Dynamics in YBa2Cu3O7
We use optical pump, coherent terahertz probe spectroscopy to transiently excite nonequilibrium populations of quasiparticles in YBa2Cu3O7−δ and monitor, with picosecond resolution, the superfluid and quasipartic...
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Article
Optimization of Materials for Thermomagnetic Cooling
We review thermoelectric transport in a magnetic field. The key physical effect for thermomagnetic cooling is the Ettingshausen effect. We describe the design principles, measurement difficulties and areas whe...
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Chapter
General Many-Body Systems
The problem of how to visualize and sometimes solve a general many-body system is considered. The ideas are established in the context of very simple small systems, a Hubbard model and a coupled electron-phono...
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Chapter
A General Theory of Inhomogeneous Systems
Inhomogeneous systems are modeled using maximum entropy methods so that only explicitly stated properties are taken into account, with no arbitrary assumptions. Sandstones are considered as an example. A phase...
