Efficient Biexciton State Preparation in a Semiconductor Quantum Dot‐Metallic Nanoparticle Hybrid Structure Using Transitionless Quantum Driving

Abstract

AbstractHow to efficiently prepare the biexciton state in a semiconductor quantum dot placed in the vicinity of a metal nanoparticle is investigated, with control pulses calculated using shortcuts to adiabaticity and specificaly transitionless quantum driving. The quantum dot is considered to be initialized in its ground state. It is numerically demonstrated that the proposed scheme can generate biexciton population values close to unity, for a broad span of interparticle distances and small to moderate values of the biexciton binding energy, when using short laser pulses. It is also shown that these results are robust for small errors in the nanoparticle placement. When the interparticle distance is decreased or the duration of the applied pulses is increased, the population transfer to the biexciton state is reduced. The reason is that for shorter distances the nonlinear terms in the density matrix equation, arising due to exciton‐plasmon interaction, become stronger, while for longer pulses the influence of these unwanted terms is prolonged. Similarly, the fidelity is also reduced for larger values of the biexciton binding energy and longer pulses. This work may be exploited in research fields like quantum information processing and high speed nanoswitches, where a key procedure is the efficient biexciton state preparation in quantum dots.