Anatoli Stepanov | Searcharxiv

arXiv2014

Rabi oscillations of solitons in spin-chains: a new route to quantum computation and communication

We provide the first evidence for coherence and Rabi oscillations of spin-solitons pinned by the local breaking of translational symmetry in isotropic Heisenberg chains (simple antiferromagnetic-Néel or spin-Peierls).We show that these correlated spin systems made of hundreds of coupled spin bear an overall spin S=1/2 and can be manipulated as a single spin. This is clearly contrary to all known spin-qubits which are paramagnetic centres, highly diluted to prevent decoherence. These results offer an alternative approach for spin-qubits paving the way for the implementation of a new type of quantum computer.

cond-mat.str-el↗

arXiv2005

Electron spin resonance in the $S$=1/2 quasi-one-dimensional antiferromagnet with Dzyaloshinskii-Moriya interaction BaCu$\_2$Ge$\_2$O$\_7$

We have investigated the electron spin resonance (ESR) on single crystals of BaCu$\_2$Ge$\_2$O$\_7$ at temperatures between 300 and 2 K and in a large frequency band, 9.6 -134 GHz, in order to test the predictions of a recent theory, proposed by Oshikawa and Affleck (OA), which describes the ESR in a $S$=1/2 Heisenberg chain with the Dzyaloshinskii-Moriya interaction. We find, in particular, that the ESR linewidth, $ΔH$, displays a rich temperature behavior. As the temperature decreases from $T\_{max}/2\approx $ 170 K to 50 K, $ΔH$ shows a rapid and linear decrease, $ΔH \sim T$. At low temperatures, below 50 K, $ΔH$ acquires a strong dependence on the magnetic field orientation and for $H \| c$ it shows a $(h/T)^2$ behavior which is due to an induced staggered field $h$, according to OA's prediction.

cond-mat.str-el↗