Japan Science and Technology Agency

Tadashi Itoh

Masaaki Ashida

Takuya Iida

Hajime Ishihara

Keiichi Edamatsu

A quantum dot manipulating method and a generation/manipulation apparatus are provided which can control the size of a large number of generated quantum dots on or below the order of percent which is required for optical applications of the dots. Quantum dots are generated by shining a dot production laser () onto a solid object () in a quantum dot production/manipulation apparatus () containing superfluid helium () therein. A dot manipulation laser () is shone onto the generated quantum dots to manipulate the quantum dots.

Quantum dot manipulating method and quantum dot production/manipulation apparatus

A laser device which causes lasing with a use of a semiconductor quantum dot is provided with: a laser member () in which the semiconductor quantum dot is formed; a resonator () for resonating light generated in the laser member (); and a pump laser () for irradiating the laser member () with excitation light whose energy corresponds to two-photon resonant excitation, so as to form a biexciton state in the semiconductor quantum dot by the two-photon resonant excitation. In this way, a laser device which enables lasing using efficient light emission is realized.

Laser device and lasing method

A CaFbuffer layer () is formed on a CaF(111) substrate () by an MBE method. Furthermore, a CuCl thin film is grown on the CaFbuffer layer () by the MBE method while irradiating it with an electron beam to form an electro beam irradiation film (). Subsequently, a CuCl thin film is grown by the MBE method without the irradiation of electron beam to form an electron beam non-irradiation film (), thereby thus forming a CuCl thin film (a) including the electron beam irradiation film () and the electron beam non-irradiation film (). Consequently, a CuCl thin film () exhibiting high planarity and crystallinity can be formed.

Group I-VII semiconductor single crystal thin film and process for producing same

A method for generating a quantum-entangled photon pair is such that a biexciton in such a state that the angular momentum is 0 is generated through two-photon resonance induced by irradiating a semiconductor substance, e.g., CuCl, with two parent photons (angular frequency &#x3c9;i). A photon pair is then generated by splitting the biexciton thus generated simultaneously into two photons (angular frequencies &#x3c9;s and &#x3c9;s'). Since the photon pair is generated by splitting such biexciton having an angular momentum of 0, it has a quantum entanglement with regard to polarization. Since the photon thus generated has a wavelength substantially equal to that of the parent photons, photons of shorter wavelength in a quantum entangled state can be generated.

Growing community of inventors

Toyonaka, Japan

Tadashi Itoh