Abstract
A Schr\"odinger-cat state is a coherent superposition of macroscopically distinguishable quantum states, in quantum optics usually realized as superposition of coherent states. Protocols to prepare photonic cats have been presented for atomic systems. Here, we investigate in what manner and how well the preparation protocols can be transferred to a solid state platform, namely a semiconductor quantum-dot--cavity system. In quantum-dot--cavity systems there are many disruptive influences like cavity losses, the radiative decay of the quantum dot, and the pure-dephasing type coupling to longitudinal acoustic phonons. We show that for one of the protocols these influences kill the quantum coherence between the states forming the cat, while for a second protocol a parameter regime can be identified where the essential characteristics of Schr\"odinger-cat states survive the environmental influences under realistic conditions.
Highlights
Schrödinger cats are probably the most popular example of highly nonclassical, purely quantum mechanical states
We have investigated two protocols for the preparation of photonic Schrödinger-cat states in the light field mode of a quantum-dot–cavity system (QDC)
We considered realistic values for the cavity losses as have been reported in QDCs, which showed that the radiative decay and cavity losses can be quite detrimental to the preparation scheme
Summary
Schrödinger cats are probably the most popular example of highly nonclassical, purely quantum mechanical states. Because of the fundamental and technological importance of Schrödinger-cat states, their preparation has long been a research target Earlier efforts in this direction focused mostly on atom-based systems, where atoms are placed in an optical losses phonons radiative decay quantum dot. The main difference between QDC and atomic systems is the presence of longitudinal acoustic phonons, which is a wellknown source of decoherence even at cryogenic temperatures of T = 4 K [39,40] It is an open question whether in the QDC platform as well the generation of Schrödinger-cat states is possible. The second protocol is adapted from Gea-Banacloche [16] and can be transferred to the QDC system by producing a coherent initial state This can be achieved by driving the cavity, we call this protocol CAD, short for cavity-driven protocol. Our work demonstrates that in QDCs the preparation of Schrödinger-cat states is possible, and we propose a protocol and specify a suitable parameter regime to prepare them
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
