Ground-state power quenching in two-state lasing quantum dot lasers

[Article] Ground-state power quenching in two-state lasing quantum dot lasers

Ground state terahertz quantum cascade lasers

A terahertz quantum cascade laser (THz QCL) architecture is presented in which only the ground state subbands of each quantum well are involved in the transport and lasing transition. Compared to state-of-the art THz QCLs based on the resonant-phonon scheme, ground state QCLs employ narrower wells so that all high-energy subbands are pushed up far above the occupied subband levels, significantl...

Spin blockade in ground state resonance of a quantum dot

– We present measurements on spin blockade in a laterally integrated quantum dot. The dot is tuned into the regime of strong Coulomb blockade, confining ∼ 50 electrons. At certain electronic states we find an additional mechanism suppressing electron transport. This we identify as spin blockade at zero bias, possibly accompanied by a change in orbital momentum in subsequent dot ground states. W...

Ground state of the parallel double quantum dot system.

We resolve the controversy regarding the ground state of the parallel double quantum dot system near half filling. The numerical renormalization group predicts an underscreened Kondo state with residual spin-1/2 magnetic moment, ln2 residual impurity entropy, and unitary conductance, while the Bethe ansatz solution predicts a fully screened impurity, regular Fermi-liquid ground state, and zero ...

Two Electron Quantum Dot - A Variational Treatment For The Ground State

A variational treatment for a two-electron quantum dot (the artificial helium atom) is proposed which leads to exact answer for the ground state energy. Depending on the magnetic field value the singlet-triplet and triplet-triplet transitions of the ground state take place, which are captured in our solution.Using the same variational technique we find corrections to wave function and energy an...