Zobrazeno 1 - 10
of 66
pro vyhledávání: '"Thuneberg, Erkki"'
We have performed numerical calculations of the structure of the single-quantum vortex in superfluid $^3$He-A. The GPU-accelerated large-scale numerical simulation is performed in the Ginzburg-Landau model and resolves length scales of both coherence
Externí odkaz:
http://arxiv.org/abs/2412.13764
Autor:
Thuneberg, Erkki
Publikováno v:
J. Low Temp. Phys. 217, 12 (2024)
We study Andreev reflection in a one-dimensional square-well pair-potential. We discuss the history of the model. The current-phase relation is presented as a sum over Matsubara frequencies. How the current arises from bound and continuum levels is f
Externí odkaz:
http://arxiv.org/abs/2405.07659
Autor:
Thuneberg, Erkki
Publikováno v:
Phys. Rev. B 108, 176501 (2023)
The old problem of supercurrent in a long ballistic SNS Josephson junction is interpreted using a simple picture of the fermion energy levels in the normal and superconducting regions. We argue that a recent paper on the topic by Sonin contains erron
Externí odkaz:
http://arxiv.org/abs/2112.07378
Publikováno v:
Phys. Rev. B 90, 184513 (2014)
We study theoretically planar interfaces between two domains of superfluid 3He-B. The structure of the B-B walls is determined on the scale of the superfluid condensation energy, and thus the domain walls have thickness on the order of the Ginzburg-L
Externí odkaz:
http://arxiv.org/abs/1408.3623
Autor:
Tuorila, Jani, Silveri, Matti, Sillanpää, Mika, Thuneberg, Erkki, Makhlin, Yuriy, Hakonen, Pertti
Publikováno v:
Supercond. Sci. Technol. 26, 124001 (2013)
We study the novel nonlinear phenomena that emerge in a charge qubit due to the interplay between a strong microwave flux drive and a periodic Josephson potential. We first analyze the system in terms of the linear Landau-Zener-St\"uckelberg model, a
Externí odkaz:
http://arxiv.org/abs/1307.6032
Publikováno v:
Phys. Rev. B 87, 134505 (2013)
The present qubit technology, in particular in Josephson qubits, allows an unprecedented control of discrete energy levels. This motivates a new study of the old pump-probe problem, where a discrete quantum system is driven by a strong drive and simu
Externí odkaz:
http://arxiv.org/abs/1301.0230
Autor:
Virtanen, Timo H., Thuneberg, Erkki
Publikováno v:
Phys. Rev. B 83, 224521 (2011)
We use Fermi liquid theory to study the mechanical impedance of 3He-4He mixtures at low temperatures. The theory is applied to the case of vibrating wires, immersed in the liquid. We present numerical results based on a direct solution of Landau-Bolt
Externí odkaz:
http://arxiv.org/abs/1101.3528
Autor:
Virtanen, Timo H., Thuneberg, Erkki
Publikováno v:
Phys. Rev. Lett. 106, 055301 (2011)
The Fermi liquid theory formulated by Landau is a basic paradigm of the behavior of an interacting many-body system. We present a new application of this theory to calculate "Landau force" on a macroscopic object. We show that immersing a pendulum in
Externí odkaz:
http://arxiv.org/abs/1010.4015
Autor:
Tuorila, Jani, Silveri, Matti, Sillanpaa, Mika, Thuneberg, Erkki, Makhlin, Yuriy, Hakonen, Pertti
Publikováno v:
Phys. Rev. Lett. 105, 257003 (2010)
A superconducting qubit was driven in an ultrastrong fashion by an oscillatory microwave field, which was created by coupling via the nonlinear Josephson energy. The observed Stark shifts of the `atomic' levels are so pronounced that corrections even
Externí odkaz:
http://arxiv.org/abs/1005.3446
Autor:
Paila, Antti, Tuorila, Jani, Sillanpää, Mika, Gunnarsson, David, Sarkar, Jayanta, Makhlin, Yuriy, Thuneberg, Erkki, Hakonen, Pertti
We investigate phase-sensitive interference effects in a periodically $\sin(2\pi f_{\rm rf} t)$-driven, artificial two-state system connected to a microwave resonator at $f_{LC} \simeq 800$ MHz. We observe two kinds of multiphoton transitions in the
Externí odkaz:
http://arxiv.org/abs/0901.1304