56 results about "Semiconductor quantum wells" patented technology

A quantum logic gate utilizes an inter-polarization (dipole-dipole) interaction between excitons having polarization in semiconductor quantum well structures, or a spin exchange interaction between spin polarized excitons in the semiconductor quantum well structures. Problems associated with conventional semiconductor quantum well structures are solved in that a phase relaxation time is very short because of using inter-subband electrons, and that there is no usable ultrashort optical pulse laser technology because a subband transition wavelength is in a far-infrared region and hence ultra fast control is impossible.

A microstrip stabilized quantum well resonance-tunneling generator which generates electromagnetic waves for millimeter and submillimeter wavelength range is provided The generator includes a resonant tunneling semiconductor quantum well diode, and a microstrip resonator. The resonant tunneling diode, the microstrip resonator and interconnecting lines and junctions are fabricated as a monolithic integrated device on a common substrate. As a result, the monolithic integrated device provides the expansion of the operation frequency range toward the terahertz region as a result of reduction of the parasitic inductance as well as of minimizing the other parasitic parameters of the electric circuitry connecting the resonant tunneling diode and resonator.

The invention discloses a terahertz wave band wireless transmitting and receiving device and a transmitting and receiving method thereof. The transmitting and receiving device comprises a transmitting terminal composed of a first cold head, a terahertz quantum-cascade laser and a first polyethylene window plate, an optical path part containing two off-axis parabolic mirrors and air and a receiving terminal composed of a second cold head, a terahertz quantum well detector and a second polyethylene window plate. The invention has the advantage that currently undistributed frequency range of electromagnetic wave is selected to transmit and receive electromagnetic wave, the absorption of the selected frequency point of electromagnetic wave by the air is relatively weaker, thus reducing the attenuation loss of terahertz wave during the transmission process; the semiconductor quantum-cascade laser which has high energy conversion efficiency and small volume, is easy to integrate, and can work for long time and perform mass production is adopted by the transmitting terminal; the semiconductor quantum well detector which has small volume, is stable and reliable and can perform mass production is adopted by the receiving terminal; and the adopted semiconductor laser and detector both can operate at high frequency, thus being suitable for future terahertz communication applications.

The invention relates to a preparation method for a bismuth-based non-rectangular group III-V semiconductor quantum well. The preparation method comprises the step of growing a potential well material and a potential barrier material of a group III-V semiconductor quantum well, wherein bismuth is added in the growth processes of both the potential well material and the potential barrier material. According to the preparation method, bismuth beam source shutters are opened simultaneously in the processes of growing the potential well material and the potential barrier material of the quantum well, and a non-rectangular quantum well structure is realized by utilizing the group III element interdiffusion caused by the bismuth. By the method, material components can be controlled effectively; the problem that the conventional growth method is only suitable for growing a rectangular quantum well structure with component mutations is solved; greater freedom is introduced to the design and the implementation of the structure and the functional of quantum; the preparation method disclosed by the invention is suitable for adopting a plurality of material growth means, such as molecular beam epitaxy and atomic layer deposition; and the operation process is simple and convenient.