arXiv subjects

Miriam Blaauboer

Publications and source records attributed to Miriam Blaauboer.

4 recordsLinked to original sources

arXiv2017

Superadiabatic quantum state transfer in spin chains

In this letter we propose a superadiabatic protocol where quantum state transfer can be achieved with arbitrarily high accuracy and minimal control across long spin chains with an odd number of spins. The quantum state transfer protocol only requires the control of the couplings between the qubits on the edge and the spin chain. We predict fidelities above 0.99 for an evolution of nanoseconds using typical spin exchange coupling values of μeV. Furthermore, by building a superadiabatic formalism on top of this protocol, we propose a effective superadiabatic protocol that retains the minimal control over the spin chain and improves the fidelity by up to 20%.

cond-mat.mes-hall↗

arXiv2014

Local Kondo temperatures in atomic chains

We study the effect of disorder in strongly interacting small atomic chains. Using the Kotliar- Ruckenstein slave-boson approach we diagonalize the Hamiltonian via scattering matrix theory. We numerically solve the Kondo transmission and the slave-boson parameters that allow us to calculate the Kondo temperature. We demonstrate that in the weak disorder regime, disorder in the energy levels of the dopants induces a non-screened disorder in the Kondo couplings of the atoms. We show that disorder increases the Kondo temperature of a perfect chain. We find that this disorder in the couplings comes from a local distribution of Kondo temperatures along the chain. We propose two experimental setups where the impact of local Kondo temperatures can be observed.

cond-mat.str-el↗

arXiv2010

Quantum pumping in a ballistic graphene bilayer

We investigate quantum pumping of massless Dirac fermions in an ideal (impurity free) double layer of graphene. The pumped current is generated by adiabatic variation of two gate voltages in the contact regions to a weakly doped double graphene sheet. At the Dirac point and for a wide bilayer with width W much larger then length L, we find that the pumped current scales linearly with the interlayer coupling length l_{perp} for L/l_{perp} << 1, is maximal for L/l_{perp} ~ 1, and crosses over to a log(L/l_{perp})/(L/l_{perp})-dependence for L/l_{perp} >> 1. We compare our results with the behavior of the conductance in the same system and discuss their experimental feasibility.

cond-mat.mes-hall↗

arXiv2002

Self-induced transparency and giant nonlinearity in doped photonic crystals

Photonic crystals doped with resonant atoms allow for uniquely advantageous nonlinear modes of optical propagation: (a) Self-induced transparency (SIT) solitons and multi-dimensional localized "bullets" propagating at photonic band gap frequencies. These modes can exist even at ultraweak intensities (few photons) and therefore differ substantially either from solitons in Kerr-nonlinear photonic crystals or from SIT solitons in uniform media. (b) Cross-coupling between pulses exhibiting electromagnetically induced transparency (EIT) and SIT gap solitons. We show that extremely strong correlations (giant cross-phase modulation) can be formed between the two pulses. These features may find applications in high-fidelity classical and quantum optical communications.

quant-ph↗