Using localized double-quantum-coherence spectroscopy to reconstruct the two-exciton wave function of coupled quantum emitters

Abstract

Coherent multidimensional spectroscopy allows us to inspect the energies and the coupling of quantum systems. Coupled quantum systems-such as a coupled semiconductor quantum dot or pigments in photosynthesis-form delocalized exciton and two-exciton states. A technique is presented to decompose these delocalized wave functions into the basis of individual quantum emitters. This quantum state tomography protocol is illustrated for three coupled InAs quantum dots. To achieve the decomposition of the wavefunction, we combine the double-quantum-coherence spectroscopy with spatiotemporal control, which allows us to localize optical excitations at a specific quantum dot. Recently, a protocol was proposed for single exciton states (Richter et al 2012 Phys . Rev. B 86 085308). In this paper, we extend the method presented by Richter et al with respect to: the reconstruction of two-exciton states, a detailed analysis process of reconstruction and the effect of filtering to enhance the quality of the reconstructed wave function.

Spatially localized spectroscopy for examining the internal structure of coupled nanostructures

“…This effectively restricts the sum in the local matrix elements to the contributions from nanosystem k . One application of this property maybe the extraction of delocalized wave functions expansion coefficients or wave functions overlaps from the local optical transition matrices, e.g., . To achieve this also the sum over the delocalized states in Eq.…”

“…We can select a specific coupling element, e.g., p gν (r k ) for a nanosystem k by manipulating the exciting electric field, so that E(r i , t) and thus A(r i , t) for i = k vanishes, i.e., the field is localized at nanosystem k [24]. This effectively restricts the sum in the local matrix elements to the contributions from nanosystem k. One application of this property maybe the extraction of delocalized wave functions expansion coefficients or wave functions overlaps [24,30] from the local optical transition matrices, e.g., p gν (r i ). To achieve this also the sum over the delocalized states in Eq.…”

Coherent control with optical pulses for deterministic spin-photon entanglement

“…[21][22][23][24][25][26] Several groups demonstrated new spin readout methods, [27][28][29] addressing one of DiVincenzo's criteria for quantum computing. 30 Impressive progress has been made recently in characterizing and manipulating InAs quantum dot molecules, 28,[31][32][33][34][35][36] including demonstration of two-qubit gates. 37 A necessary next step for quantum dot based quantum computing is to extend such results to many-qubit systems.…”

Enhanced TEMPO algorithm for quantum path integrals with off-diagonal system-bath coupling: applications to photonic quantum networks

“…5(b),indicates that these match well with transitions between the first and second rung of the JCM ladder. The single and double quantum correlation function give the coherences of a system between ground state and single or double excitation states (respectively) [51][52][53][54]; (see [39] for further details). Other (positive) contributions between the first and second rung are overlapping with resonances 1 and 2, which slightly affect their line shape.…”