The valley Zeeman effect in inter- and intra-valley trions in monolayer WSe2

Abstract

Monolayer transition metal dichalcogenides (TMDs) hold great promise for future information processing applications utilizing a combination of electron spin and valley pseudospin. This unique spin system has led to observation of the valley Zeeman effect in neutral and charged excitonic resonances under applied magnetic fields. However, reported values of the trion valley Zeeman splitting remain highly inconsistent across studies. Here, we utilize high quality hBN encapsulated monolayer WSe 2 to enable simultaneous measurement of both intervalley and intravalley trion photoluminescence. We find the valley Zeeman splitting of each trion state to be describable only by a combination of three distinct g-factors, one arising from the exciton-like valley Zeeman effect, the other two, trion specific, g-factors associated with recoil of the excess electron. This complex picture goes significantly beyond the valley Zeeman effect reported for neutral excitons, and eliminates the ambiguity surrounding the magneto-optical response of trions in tungsten based TMD monolayers.

Interplay between spin proximity effect and charge-dependent exciton dynamics in MoSe2/CrBr3 van der Waals heterostructures

“…2b) 35,46 . This intervalley ground state is highly favored over the intravalley trion configuration, for which the large~200 meV spin-orbit coupling strength in the VB is prohibitive 35,[46][47][48] . The electron spin is tied to the emission helicity owing to optical selection rules and spin-valley locking 29,46 .…”

Valley phonons and exciton complexes in a monolayer semiconductor

“…Finally, we note that Γ 5 + appears 22 meV below + , which is consistent with the recently reported Γ 5 phonon replica of D + . 12 To further examine these assignments, we performed magneto-PL to extract the effective Landé g-factors of the various states, which are then used to identify the spin and valley indices of the constituent electrons and holes in the excitonic states [36][37][38][39][40] . The extracted g-factors of the states of interest are listed in Table 1.…”

Ultra-long-working-distance spectroscopy of single nanostructures with aspherical solid immersion microlenses

“…The interest in monolayer and few-layer S-TMDs and other 2D materials results from their unique electronic and optical properties 31 as well as their mutual compatibility, which opens up the possibility of stacking them to form artificial crystals with tailored properties 32 . The S-TMDs, with a non-zero bandgap, are particularly well suited for optical applications, including optoelectronic sensors and light emitters [33][34][35][36][37][38] . We decided to use two popular representatives of the S-TMD family, namely, monolayer WSe 2 and monolayer MoSe 2 .…”