Abstract:
Embodiments of the present disclosure provide quantum circuit assemblies that implement adaptive programming of quantum dot qubit devices. An example quantum circuit assembly includes a quantum circuit component including a quantum dot qubit device, and a control logic coupled to the quantum circuit component. The control logic is configured to adaptively program the quantum dot qubit device by iterating a sequence of applying one or more signals to the quantum dot qubit device, determining a state of at least one qubit of the quantum dot qubit device, and using the determined state to modify the signals to be applied to the quantum dot qubit device in the next iteration. In this manner, the signals may be fine-tuned to achieve a higher probability of the qubit(s) in the quantum dot qubit device being set to the desired state.
Abstract:
Disclosed herein are quantum dot devices, as well as related computing devices and methods. For example, in some embodiments, a quantum dot device may include a base and a fin extending away from the base and including a quantum well layer. The device may further include a first gate disposed on a first side of the fin and a second gate disposed on a second side of the fin, different from the first side. Providing gates on different sides of a fin advantageously allows increasing the number of quantum dots which may be independently formed and manipulated in the fin. The quantum dots formed in such a device may be constrained in the x-direction by the one or more gates, in the y-direction by the fin, and in the z-direction by the quantum well layer, as discussed in detail herein. Methods for fabricating such devices are also disclosed.
Abstract:
Disclosed herein are quantum dot devices, as well as related computing devices and methods. For example, in some embodiments, a quantum dot device may include: a quantum well stack including a quantum well layer, a doped layer, and a barrier layer disposed between the doped layer and the quantum well layer; and gates disposed above the quantum well stack. In some embodiments, a quantum dot device may include: a fin extending away from a base and having insulating material disposed on at least two opposing faces of the fin, wherein the fin includes a quantum well stack and the quantum well stack includes a quantum well layer, a doped layer, and a barrier layer disposed between the doped layer and the quantum well layer; and gates disposed above the quantum well stack.
Abstract:
Disclosed herein are quantum dot devices, as well as related computing devices and methods. For example, in some embodiments, a quantum dot device may include: a base; a fin extending away from the base, wherein the fin includes a quantum well layer; and one or more gates disposed on the fin. In some such embodiments, the one or more gates may include first, second, and third gates. Spacers may be disposed on the sides of the first and second gates, such that a first spacer is disposed on a side of the first gate proximate to the second gate, and a second spacer, physically separate from the first spacer, is disposed on a side of the second gate proximate to the first gate. The third gate may be disposed on the fin between the first and second gates and extend between the first and second spacers.
Abstract:
Disclosed herein are quantum dot devices, as well as related computing devices and methods. For example, in some embodiments, a quantum dot device may include: a quantum well stack; a plurality of first gates disposed on the quantum well stack; a plurality of pairs of spacers, each pair of spacers disposed on opposites sides of an associated first gate, wherein each spacer in a pair has a curved surface that curves away from the associated first gate; and a plurality of second gates disposed on the quantum well stack, wherein the curved surface of each spacer is adjacent to one of the second gates such that at least a portion of each second gate is shaped complementarily to the curved surface of an adjacent spacer.
Abstract:
The invention relates to a memory cell (10) comprising at least one binary memory area for storing an item of bit information and to a method for storing an item of bit information. According to the invention, it is provided that the memory area (SB), e.g. a quantum dot layer of In(Ga)As quantum dots, can optionally store holes or electrons and allows a recombination of holes and electrons, the charge carrier type of the charge carriers stored in the memory area defines the bit information of the memory area and a charge carrier injection device (PN) is present, by means of which optionally holes or electrons can be injected into the memory area (SB) and the bit information can thus be changed. The holes and electrons come from a hole reservoir (LR) or electron reservoir (ER) which consist e.g. of p-doped or n-doped GaAs. The readout layer (AS) is a two-dimensional hole or electron gas layer.