Rainer Kühne

Dr. Rainer Kühne

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Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 1999 in Physical Review B
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Rainer KühneRainer Kühne
Rainer Kühne
ULUte Löw
Ute Löw
We performed a finite-temperature quantum Monte Carlo simulation of the one-dimensional spin-12 Heisenberg model with nearest-neighbor interaction coupled to Einstein phonons. Our method allows us to treat easily up to 100 phonons per site and the results presented are practically free from truncation errors. We studied in detail the magnetic susceptibility, the specific heat, the phonon occupation, the dimerization, and the spin-correlation function for various spin-phonon couplings and phonon frequencies. In particular we give evidence for the transition from a gapless to a massive phase by studying the finite-size behavior of the susceptibility. We also show that the dimerization is proportional to g2/Ω for T<2J.

28 December 1997 in Modern Physics Letters A
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Rainer KühneRainer Kühne
Rainer Kühne

20 October 1997 in Modern Physics Letters A
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Rainer KühneRainer Kühne
Rainer Kühne

3 April 2002 in Physical Review B
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CRCarsten Raas
Carsten Raas
ULUte Löw
Ute Löw
GUGötz S. Uhrig
Götz S. Uhrig
Rainer KühneRainer Kühne
Rainer Kühne
We investigate the antiadiabatic limit of an antiferromagnetic S=1/2 Heisenberg chain coupled to Einstein phonons via a bond coupling. The flow equation method is used to decouple the spin and the phonon part of the Hamiltonian. In the effective spin model longer range spin-spin interactions are generated. The effective spin chain is frustrated. The resulting temperature-dependent couplings are used to determine the magnetic susceptibility and to determine the phase transition from a gapless state to a dimerized gapped phase. The susceptibilities and the phase diagram obtained via the effective couplings are compared with independently calculated quantum Monte Carlo results.

2 September 2019 in OSF Preprints
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Rainer KühneRainer Kühne
Rainer Kühne
Climate activist Greta Thunberg started her Skolstrejk för Klimatet on 20 August 2018. Her activity inspired the weekly international demonstrations of Fridays for Future. In this paper I review the scientific argumentation that justifies the demonstrations.

7 September 1999 in Modern Physics Letters A
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Rainer KühneRainer Kühne
Rainer Kühne