Abstract: An array of spin qubits relies on a gradient magnetic field to ensure that the qubits are separated in frequency in order to be individually addressable. Furthermore, a strong magnetic field gradient is required to electrically drive the EDSR of the qubits. Quantum dot devices and related methods and systems that integrate magnetic materials in the gates to provide a gradient magnetic field are disclosed. Magnetic materials in different gates may be of different heights to improve frequency separation of neighboring qubits. Unlike previous approaches to quantum dot formation and manipulation, various embodiments of the quantum dot devices disclosed herein may enable improved control over magnetic fields and their gradients to realize better frequency targeting of individual qubits, help minimize adverse effects of charge noise on qubit decoherence and provide good scalability in the number of quantum dots included in the device.

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 structure of a quantum dot device, wherein the quantum well stack structure includes an insulating material to define multiple rows of quantum dot formation regions; and a gate that extends over multiple ones of the rows.

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 structure of a quantum dot device, wherein the quantum well stack structure includes an insulating material to define multiple rows of quantum dot formation regions; and a gate that extends over multiple ones of the rows.

Abstract: Quantum dot devices, and related systems and methods, are disclosed herein. In some embodiments, a quantum dot device may include a quantum well stack; a plurality of first gates above the quantum well stack; and a plurality of second gates above the quantum well stack; wherein the plurality of first gates are arranged in electrically continuous rows extending in a first direction, and the plurality of second gates are arranged in electrically continuous rows extending in a second direction perpendicular to the first direction.

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 substrate and a quantum well stack disposed on the substrate. The quantum well stack may include a quantum well layer and a back gate, and the back gate may be disposed between the quantum well layer and the substrate.

Abstract: Quantum dot devices, and related systems and methods, are disclosed herein. In some embodiments, a quantum dot device may include a quantum well stack; a plurality of first gates above the quantum well stack; and a plurality of second gates above the quantum well stack; wherein the plurality of first gates are arranged in electrically continuous rows extending in a first direction, and the plurality of second gates are arranged in electrically continuous rows extending in a second direction perpendicular to the first direction.

Abstract: An array of quantum dot qubits (e.g., an array of spin qubits) relies on a gradient magnetic field to ensure that the qubits are separated in frequency in order to be individually addressable. Furthermore, a strong magnetic field gradient is required to electrically drive the electric dipole spin resonance (EDSR) of the qubits. Quantum dot devices disclosed herein use microcoil arrangements for providing a gradient magnetic field, the microcoil arrangements integrated on the same chip (e.g., on the same die or wafer) as quantum dot qubits themselves. Unlike previous approaches to quantum dot formation and manipulation, various embodiments of the quantum dot devices disclosed herein may enable improved control over magnetic fields and their gradients to realize better frequency targeting of individual qubits, help minimize adverse effects of charge noise on qubit decoherence and provide good scalability in the number of quantum dots included in the device.

Abstract: An array of quantum dot qubits (e.g., an array of spin qubits) relies on a gradient magnetic field to ensure that the qubits are separated in frequency in order to be individually addressable. Furthermore, a strong magnetic field gradient is required to electrically drive the electric dipole spin resonance (EDSR) of the qubits. Quantum dot devices disclosed herein use microcoil arrangements for providing a gradient magnetic field, the microcoil arrangements integrated on the same chip (e.g., on the same die or wafer) as quantum dot qubits themselves. Unlike previous approaches to quantum dot formation and manipulation, various embodiments of the quantum dot devices disclosed herein may enable improved control over magnetic fields and their gradients to realize better frequency targeting of individual qubits, help minimize adverse effects of charge noise on qubit decoherence and provide good scalability in the number of quantum dots included in the device.

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 first gate above the quantum well stack, wherein the first gate includes a first gate metal and a first gate dielectric; and a second gate above the quantum well stack, wherein the second gate includes a second gate metal and a second gate dielectric, and the first gate is at least partially between a portion of the second gate and 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 quantum well stack; a first gate and an adjacent second gate above the quantum well stack; and a gate wall between the first gate and the second gate, wherein the gate wall includes a spacer and a capping material, the spacer has a top and a bottom, the bottom of the spacer is between the top of the spacer and the quantum well stack, and the capping material is proximate to the top of the spacer.

Abstract: Quantum dot devices, and related systems and methods, are disclosed herein. In some embodiments, a quantum dot device may include a quantum well stack; a plurality of first gates above the quantum well stack; and a plurality of second gates above the quantum well stack; wherein the plurality of first gates are arranged in electrically continuous rows extending in a first direction, and the plurality of second gates are arranged in electrically continuous rows extending in a second direction perpendicular to the first direction.

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 substrate and a quantum well stack disposed on the substrate. The quantum well stack may include a quantum well layer and a back gate, and the back gate may be disposed between the quantum well layer and the substrate.

Abstract: Disclosed herein are quantum dot devices with trenched substrates, as well as related computing devices and methods. For example, in some embodiments, a quantum dot device may include: a substrate having a trench disposed therein, wherein a bottom of the trench is provided by a first material, and a quantum well stack at least partially disposed in the trench. A material of the quantum well stack may be in contact with the bottom of the trench, and the material of the quantum well stack may be different from the first material.

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, wherein the quantum well layer includes an isotopically purified material; a gate dielectric above the quantum well stack; and a gate metal above the gate dielectric, wherein the gate dielectric is between the quantum well layer and the gate metal.

Abstract: Disclosed herein are quantum dot devices with multiple layers of gate metal, as well as related computing devices and methods. For example, in some embodiments, a quantum dot device may include: a quantum well stack; an insulating material above the quantum well stack, wherein the insulating material includes a trench; and a gate on the insulating material and extending into the trench, wherein the gate includes a first gate metal in the trench and a second gate metal above the first gate metal.

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 substrate and a quantum well stack disposed on the substrate. The quantum well stack may include a quantum well layer and a back gate, and the back gate may be disposed between the quantum well layer and the substrate.

Abstract: Quantum dot devices, and related systems and methods, are disclosed herein. In some embodiments, a quantum dot device may include a quantum well stack; a plurality of first gates above the quantum well stack; and a plurality of second gates above the quantum well stack; wherein the plurality of first gates are arranged in electrically continuous rows extending in a first direction, and the plurality of second gates are arranged in electrically continuous rows extending in a second direction perpendicular to the first direction.

Abstract: An array of quantum dot qubits (e.g., an array of spin qubits) relies on a gradient magnetic field to ensure that the qubits are separated in frequency in order to be individually addressable. Furthermore, a strong magnetic field gradient is required to electrically drive the electric dipole spin resonance (EDSR) of the qubits. Quantum dot devices disclosed herein use microcoil arrangements for providing a gradient magnetic field, the microcoil arrangements integrated on the same chip (e.g., on the same die or wafer) as quantum dot qubits themselves. Unlike previous approaches to quantum dot formation and manipulation, various embodiments of the quantum dot devices disclosed herein may enable improved control over magnetic fields and their gradients to realize better frequency targeting of individual qubits, help minimize adverse effects of charge noise on qubit decoherence and provide good scalability in the number of quantum dots included in the device.

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 and a plurality of linear arrays of gates above the quantum well stack to control quantum dot formation in the quantum well stack. An insulating material may be between a first linear array of gates and a second linear array of gates, the insulating material may be between individual gates in the first linear array of gates, and gate metal of the first linear array of gates may extend over the insulating material.

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 (111) silicon substrate, a (111) germanium quantum well layer above the substrate, and a plurality of gates above the quantum well layer. In some embodiments, a quantum dot device may include a silicon substrate, an insulating material above the silicon substrate, a quantum well layer above the insulating material, and a plurality of gates above the quantum well layer.