Single and Double Hole Quantum Dots in Strained Ge/SiGe Quantum Wells

Abstract

Even as today's most prominent spin-based qubit technologies are maturing in terms of capability and sophistication, there is growing interest in exploring alternate material platforms that may provide advantages, such as enhanced qubit control, longer coherence times, and improved extensibility. Recent advances in heterostructure material growth have opened new possibilities for employing hole spins in semiconductors for qubit applications. Undoped, strained Ge/SiGe quantum wells are promising candidate hosts for hole spin-based qubits due to their low disorder, large intrinsic spin-orbit coupling strength, and absence of valley states. Here, we use a simple one-layer gated device structure to demonstrate both a single quantum dot as well as coupling between two adjacent quantum dots. The hole effective mass in these undoped structures, $m$* ~ 0.08 $m$${}_0$, is significantly lower than for electrons in Si/SiGe, pointing to the possibility of enhanced tunnel couplings in quantum dots and favorable qubit-qubit interactions in an industry-compatible semiconductor platform.

arXiv comment20 pages, 5 figures including supporting information

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Cited by in corpus (18)

• The germanium quantum information route
• A single-hole spin qubit
• Review of performance metrics of spin qubits in gated semiconducting nanostructures
• Theory of Hole-Spin Qubits in Strained Germanium Quantum Dots
• Optimal operation points for ultrafast, highly coherent Ge hole spin-orbit qubits
• Light effective hole mass in undoped Ge/SiGe quantum wells
• Charge-noise induced dephasing in silicon hole-spin qubits
• Cavity Control over Heavy-Hole Spin Qubits in Inversion-Symmetric Crystals
• Exchange interaction of hole-spin qubits in double quantum dots in highly anisotropic semiconductors
• Electrical operation of hole spin qubits in planar MOS silicon quantum dots
• Anisotropic $g$-tensors in hole quantum dots: The role of the transverse confinement direction
• Democratizing Spin Qubits
• High quality CVD deposition of Ge layers for Ge/SiGe Quantum Well heterostructures
• Low-temperature environments for quantum computation and quantum simulation
• Predicting Solid State Material Platforms for Quantum Technologies
• Effective out-of-plane g-factor in strained-Ge/SiGe quantum dots
• Robust entangling gate for capacitively coupled few-electron singlet-triplet qubits
• Thermal activation of low-density Ga implanted in Ge