Hyperentanglement source by intersubband two-photon emission from semiconductor quantum wells

Abstract

We propose an efficient hyperentanglement source emitting photon pairs entangled in both energy and polarization. The compact electrically driven room-temperature source, based on intersubband two-photon emission from semiconductor quantum wells (QWs) exhibits pair generation rates several orders of magnitude higher than alternative conventional schemes. A theoretical formalism is derived for the calculation of photon pair generation spectra and rates. The results are presented for superlattice structures similar to quantum cascade lasers of GaAs/AlGaAs QWs emitting in the mid-IR and far-IR and for InN/AlN QW structures suitable for telecommunication wavelengths.

Photon energy entanglement characterization by electronic transition interference

“…Carrier density control is more feasible; however it still suffers from low interference contrast [41]. The most practical method to mitigate TPA cross-couplings is the use of polarization selection rules [17,42], so that Ω 1 + ω 1 and Ω 2 + ω 2 absorption is allowed, whereas Ω 2 + ω 1 and Ω 1 + ω 2 is forbidden.…”

Proposal for on-chip generation and control of photon hyperentanglement

“…In fact, generated photons are often entangled in more than one DOF, or hyperentangled [6]. Such states can improve the reliability of quantum interference experiments [7] and have other uses in quantum information [8][9][10].…”

Measurement and Model of the Infrared Two-Photon Emission Spectrum of GaAs

“…TPE in condensed matter and specifically in semiconductors was only recently observed, exhibiting emission rates nearly 5 orders of magnitude weaker than one-photon processes and nonradiative transitions [4]. This phenomenon opens a wide range of possible applications including efficient electrically driven heralded single photon sources and entanglement sources [5,6]. Moreover, it is a crucial effect for future semiconductor two-photon amplifiers [7][8][9] and lasers [10] allowing ultrashort optical pulse generation due to the nonlinearity and the wide bandwidth of two-photon gain.…”

“…The final expression [Eq. (6)] is derived by taking the weak-field limit-namely the first term in Taylor expansion-and by including a symmetrical Feynman diagram term [ Fig. 1(c)], where the first and second photon frequencies are interchanged resulting in…”