In semiconductor physics, many essential optoelectronic material parameters can be experimentally revealed via optical spectroscopy in sufficiently large magnetic fields. For monolayer transition-metal dichalcogenide semiconductors, this field scale is substantial-tens of teslas or more-due to heavy carrier masses and huge exciton binding energies. Here we report absorption [Formula: see text], text] very high fields 91 T. We follow the diamagnetic shifts valley Zeeman splittings not only...

Two coupled CdTe quantum dots, selected from a self-assembled system, one of them containing single Mn ion, were studied by continuous wave and modulated photoluminescence, photoluminescence excitation, photon correlation experiments. Optical writing information on the spin state ion has been demonstrated, using orientation spin-polarized carriers transferred neighboring dot. time values 20 to 100 ns measured, depending excitation power. Storage was found be enhanced application static...

Solotronics, optoelectronics based on solitary dopants, is an emerging field of research and technology reaching the ultimate limit miniaturization. It aims at exploiting quantum properties individual ions or defects embedded in a semiconductor matrix. As already shown, optical control spin magnetic ion feasible employing photo-generated carriers confined dot. A non-radiative recombination, regarded as severe problem, limited development dots with ions. Our photoluminescence studies on, so...

A recently discovered class of two-dimensional semiconductors exhibits a novel degree freedom known as valley pseudospin. New results show that weak magnetic field can significantly extend the depolarization time this

Abstract Single impurities with nonzero spin and multiple ground states offer a degree of freedom that can be utilized to store the quantum information. However, Fe 2+ dopant is known for having single nondegenerate state in bulk host semiconductors thus little use spintronic applications. Here we show well-established picture configuration modified by subjecting ion high strain, example, produced lattice mismatched epitaxial nanostructures. Our analysis reveals strain induces qualitative...

Using time-resolved optical Kerr rotation, we measure the low temperature valley dynamics of resident electrons and holes in exfoliated WSe$_2$ monolayers as a systematic function carrier density. In an effort to reconcile many disparate timescales monolayer semiconductors reported date, directly compare doping-dependent relaxation two electrostatically-gated having different dielectric environments. fully-encapsulated structure (hBN/WSe$_2$/hBN, where hBN is hexagonal boron nitride), found...

Systematic measurements of auto- and cross-correlations photons emitted from individual $\mathrm{Cd}\mathrm{Te}∕\mathrm{Zn}\mathrm{Te}$ quantum dots under pulsed excitation were used to elucidate nonresonant mechanisms in this self-assembled system. Memory effects extending over a few pulses have been detected agreement with previous reports quantitatively described by rate equation model, fitting complete set correlation PL intensity results. The important role single carrier trapping the...

A promising method to investigate dark exciton transitions in quantum dots is presented. The optical recombination of the allowed when state coupled with an individual magnetic impurity (manganese ion). It shown that efficient radiative possible exchange interaction ion accompanied by a mixing heavy-light hole states related in-plane anisotropy dot. also channel manganese spin orientation.

We demonstrate evidence for a radiative recombination channel of dark excitons in self-assembled quantum dots. This is due to light hole admixture the excitonic ground state. Its presence was experimentally confirmed by direct observation exciton photoluminescence from cleaved edge sample. The polarization resolved measurements revealed that photon created emitted only direction perpendicular growth axis. Strong correlation between lifetime and in-plane g-factor enabled us show dominant...

2D magnetic semiconductors, which intrinsically couple a rich landscape of orders with tightly bound electron-hole pairs (excitons), present an exciting platform to investigate the interplay between optical and phenomena at atomic scale. In such systems, strength magneto-optical effects determines how deeply properties can be revealed. Here, we report observation remarkably strong magneto-excitonic in semiconductor CrSBr that allow probing its order unprecedented sensitivity. By...

The evolution of the magnetization in (Cd,Mn)Te quantum wells after a short pulse magnetic field was determined from giant Zeeman shift spectroscopic lines. dynamics absence static found to be up 3 orders magnitude faster than that at 1 T. Hyperfine interaction and strain are mainly responsible for fast decay. influence hole gas is clearly visible: zero anisotropic holes stabilize system Mn ions, while T they known speed decay by opening an additional relaxation channel.

We present a comprehensive photoluminescence study of exchange interaction in self-assembled CdTe/ZnTe quantum dots. exploit the presence multiple charge states spectra single dots to analyze simultaneously fine structure different excitonic transitions, including recombination neutral exciton/biexciton, doubly charged negative exciton and negatively biexciton. demonstrate that results from electron-hole spin Hamiltonians with effective constants $\delta_i$ can provide good description each...

We present direct observation of a coherent spin precession an individual Mn2+ ion, having both electronic and nuclear spins equal to 5/2, embedded in CdTe quantum dot placed magnetic field. The state evolution is probed time-resolved pump-probe measurement absorption the single dot. experiment reveals subtle details large-spin dynamics, such as nonsinusoidal states occupation, beatings caused by strain-induced differences energy levels separation. Sensitivity impurity on crystal strain...

The quantum confinement in a typical dot (QD) is determined primarily by the nanosystem's dimensions and average composition. We demonstrate, however, that excitonic properties of natural QDs formed InAs/GaAs wetting layer are governed predominantly effects random fluctuations lattice It shown biexciton binding energy very sensitive function randomness with nearly flat dependence on exciton energy. large variation different realizations QD structure to lead some cases reversal order lines....

Arrays of nanomagnets known as artificial spin ice can host high densities mobile magnetic monopolelike quasiparticles at room temperature, opening the door to new studies charges in synthetic matter.

We present a spectroscopic study of excitation dynamics in self assembled CdTe/ZnTe quantum dots. Insight into details kinetics is obtained from the time resolved micro-photoluminescence, single photon correlation and subpicosecond measurements done on It shown that pulsed energy above gap barrier material results separate capture electrons holes. The carriers different charge take place at delay excitation.

We show theoretically and experimentally the existence of a new quantum-interference effect between electron-hole interactions scattering by single Mn impurity. The theoretical model, including electron--valence-hole correlations, short- long-range exchange interaction ion with heavy hole electron anisotropy quantum dot, is compared photoluminescence spectroscopy CdTe dots magnetic ions. how design electronic levels dot enables an exciton, control interference, hence engineering light-Mn interaction.

We report on the method of fabrication a photonic microstructure that contains single magnetic ion. Exactly one manganese ion was introduced into self-assembled CdTe quantum dot, which located in ZnTe based micropillar cavity. The multistep procedure includes molecular beam epitaxy growth, optical characterization, and focused etching. Realization structure confirmed by observation spectroscopic exciton lines split six due to exchange interaction with cavity mode tuned dot emission energy...

We report magnetoabsorption spectroscopy of gated WSe_{2} monolayers in high magnetic fields up to 60 T. When doped with a 2D Fermi sea mobile holes, well-resolved sequences optical transitions are observed both σ^{±} circular polarizations, which unambiguously and separately indicate the number filled Landau levels (LLs) K K^{'} valleys. This reveals interaction-enhanced valley Zeeman energy, is found be highly tunable hole density p. exploit this tunability align LLs K^{'}, find that gas...

We show theoretically and experimentally that the ground state of a biexciton in CdTe self-assembled quantum dot with magnetic Mn impurity exhibits fine structure due to electron-electron Coulomb electron-Mn exchange interactions. Results exact diagonalization microscopic biexciton-manganese-ion model predict pattern three pairs states ground-state manifold, each pair labeled by projection spin. determines ordering emission maxima can be derived from exciton spectra. Theoretical predictions...

We study the biexciton formation process in a single CdTe/ZnTe quantum dot. Consistently with previous studies, we find subquadratic dependence of photoluminescence intensity on excitation power. quantitatively explain this terms interplay between two alternative mechanisms, including from long-lived dark exciton residing This mechanism is demonstrated to be dominant one for wide range intensities. Our complemented by determination characteristic time, which shown governed spin relaxation...

Together with charge and spin, many novel two-dimensional materials also permit information to be encoded in an electron's valley degree of freedom-that is, particular momentum states the material's Brillouin zone. With a view toward valley-based (opto)electronic technologies, intrinsic time scales scattering are therefore fundamental interest. Here, we demonstrate entirely noise-based approach for exploring dynamics monolayer transition-metal dichalcogenide semiconductors. Exploiting their...

In monolayer transition-metal dichalcogenide semiconductors, many-body correlations can manifest in optical spectra when electron-hole pairs (excitons) are photoexcited into a 2D Fermi sea of mobile carriers. At low carrier densities, the formation charged excitons (X±) is well documented. However, WSe2 monolayers, an additional absorption resonance, often called X-', emerges at high electron density. Its origin not understood. Here, we investigate X-' state via polarized spectroscopy gated...

Complex charge variation processes in low-density, direct-type GaAlAs quantum dots embedded a type-II GaAs/AlAs bilayer are studied by single-photon correlation measurements. Two groups of excitonic transitions distinguished the single dot (QD) photoluminescence spectra, namely due to recombination neutral and charged multiexcitonic complexes. The radiative cascades found within each group. Three characteristic time scales identified QD emission dynamics. fastest one (of order 1 ns) is...

We study the impact of nanowire shape anisotropy on spin splitting excitonic photoluminescence. The experiments are performed individual ZnMnTe/ZnMgTe core/shell nanowires as well ZnTe/ZnMgTe containing optically active magnetic CdMnTe insertions. When field is oriented parallel to axis, several times larger than for perpendicular field. interpret this pronounced an effect mixing valence band states arising from strain present in geometry. This interpretation further supported by theoretical...