arXiv subjects

Weizhao Wang

Publications and source records attributed to Weizhao Wang.

4 recordsLinked to original sources

arXiv2026

Growth and fabrication of advanced PbTe-Pb quantum devices

We report recent progress in the growth and fabrication of advanced PbTe-Pb Majorana devices for three-terminal correlation experiments. A critical prerequisite for these devices is a continuous Pb film spanning from the PbTe nanowire to the substrate. In previous studies, PbTe nanowires were spatially separated from the substrate mask, making them unable to fulfill this requirement. To address this issue, we have developed a new growth and fabrication approach. Key fabrication steps are introduced between the PbTe growth and Pb deposition. The top facet of the PbTe nanowire is covered with a Te capping layer before breaking the ultra-high vacuum, enabling ex situ processing for subsequent steps. The mask is then removed, followed by the fabrication of shadow walls. After reloading the chip into the growth chamber, the Te protection layer is removed through thermal decomposition, and the Pb film is subsequently deposited. Notably, a pristine PbTe-Pb interface with an in-situ-equivalent quality can be achieved despite the ex-situ processing. Our technique facilitates the develop of advanced PbTe-Pb quantum devices with complex designs, paving the way toward the realization of topological qubits.

cond-mat.mes-hall↗

arXiv2026

Gate-tunable superconductor-semiconductor coupling and its impact on zero-energy modes in PbTe-Pb nanowires

Superconductor-semiconductor coupling in hybrid nanowires plays a pivotal role in Majorana devices. Here, we demonstrate this tunable coupling in PbTe-Pb nanowires and its impact on the induced gap and zero-bias peaks (ZBPs). In the strong coupling regime, the device reveals a clean superconducting gap, where robust and non-robust ZBPs are observed in distinct magnetic field ranges. Conversely, increasing the gate voltage drives the system toward the weak coupling regime, where the gap becomes narrow and soft. Consequently, robust ZBPs disappear while non-robust ones persist. Our results establish a direct link between tunable coupling and robust ZBPs, providing guidelines on engineering Majorana zero modes and topological qubits.

cond-mat.mes-hall↗

arXiv2026

Presence versus absence of charging energies in PbTe quantum dots

Charging energy ($E_C$) is essential in quantum dot (QD) devices. Previous studies on PbTe QDs have reported both the presence and absence of $E_C$. To resolve this ambiguity, we vary the QD size, i.e. the cross-sectional area of PbTe nanowires, and track the evolution of $E_C$. For large crosssectional areas ($\sim$ 16000 nm$^2$), the PbTe QDs exhibit no measurable $E_C$, while quantized levels are well resolved. Decreasing this area successively to 5000, 1500, and 460 nm$^2$, $E_C$ becomes finite and increases to 80, 160, and 210 $μ$eV, respectively. We further demonstrate the strong tunability of local gates, which can tune the PbTe device from the QD regime to the regime of ballistic transport. These results address concerns regarding the large dielectric constant of PbTe and provide key insights in engineering advanced PbTe quantum devices.

cond-mat.mes-hall↗

arXiv2025

Seasonality in the U.S. Housing Market: Post-Pandemic Shifts and Regional Dynamics

Seasonality has traditionally shaped the U.S. housing market, with activity peaking in spring-summer and declining in autumn-winter. However, recent disruptions, particularly post-COVID-19, raise questions about shift in these patterns. This study analyzes housing market date (1991-2024) to examine evolving seasonality and regional heterogeneity. Using Housing Price Index (HPI), inventory and sales data from the Federal Housing Finance Agency and U.S. Census Bureau, seasonal components are extracted via the X-13-ARIMA procedure, and statistical tests assess variations across regions. The results confirm seasonal fluctuations in prices and volumes, with recent shifts toward earlier annual peak (March-April) and amplified seasonal effects. Regional variations align with differences in climate and market structure, while prices and sales volumes exhibit in-phase movement, suggesting thick-market momentum behaviour. These findings highlight key implications for policymakers, realtors and investors navigating post-pandemic market dynamics, offering insights into the timing and interpretation of housing market activities.

econ.GN↗