Technische Unversität Berlin

Andrei Schliwa

Dieter Bimberg

André Strittmatter

Tim David Germann

Udo W Pohl

Jan-Hindrik Schulze

Vladimir Gaysler

Momme Winkelnkemper

Erik Stock

Ludwig Greif

The invention relates to a method for the production of a photon pair source, which generates entangled photon pairs, having at least one quantum dot, wherein in the method the operational behaviour of the photon pair source is determined by adjusting the fine structure splitting of the excitonic energy level of the at least one quantum dot. It is provided according to the invention for the fine structure splitting of the excitonic energy level to be adjusted by depositing the at least one quantum dot on a {111} crystal surface of a semiconductor substrate.

Photon pair source and method for its production

A device including a locally modified buried first layer. A second layer is arranged on top of the first layer. The first layer includes at least one modified section and at least one unmodified section. The modified material of the locally modified buried first layer changes or induces mechanical strain in a portion of the second layer which is arranged above the at least one modified section. At least one nanostructure is placed on top of the second layer in an area, which is located above the at least one unmodified section of the first layer or adjacent thereto, said at least one nanostructure being formed by a strain-sensitive third material deposited on the locally strained second layer.

Layer assembly

The invention inter alia relates to a method of fabricating a layer assembly comprising the steps of: arranging a first layer on top of a carrier; arranging a second layer on top of the first layer; locally modifying the material of the buried first layer and providing at least one modified section in the first layer, wherein the modified material changes or induces mechanical strain in a portion of the second layer which is arranged above the at least one modified section; after locally modifying the material of the buried first layer, depositing a third material on top of the second layer, at least one characteristic of the third material being sensitive to the local mechanical strain in the second layer.

An embodiment of the invention relates to a single-photon source for emitting single photons, comprising a cavity having a first mirror and a second mirror and exhibiting a longitudinal resonance frequency between the first and second mirror; at least one quantum dot arranged inside said cavity, said quantum dot being strain-dependent and configured to generate radiation at a strain-dependent radiation frequency; a device capable of exciting the quantum dot to generate radiation; a piezoelectric crystal being arranged outside the cavity and mechanically coupled to the second mirror's outer surface, said piezoelectric crystal configured to receive a control voltage and capable of applying either a laterally tensile and vertically compressive strain to both the cavity and the quantum dot, or a laterally compressive and vertically tensile strain to both the cavity and the quantum dot, depending on the control voltage's polarity; wherein, in response to said strain, the resonance frequency and the radiation frequency shift in opposite directions.

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Storkow, Germany

Andrei Schliwa