arXiv subjects

N. Deshpande

Publications and source records attributed to N. Deshpande.

5 recordsLinked to original sources

arXiv2025

Voltage Noise Thermometry in Integrated Circuits at Millikelvin Temperatures

This paper demonstrates the use of voltage noise thermometry, with a cross-correlation technique, as a dissipation-free method of thermometry inside a CMOS integrated circuit (IC). We show that this technique exhibits broad agreement with the refrigerator temperature range from 300 mK to 8 K. Furthermore, it shows substantial agreement with both an independent in-IC thermometry technique and a simple thermal model as a function of power dissipation inside the IC. As the device under test (DUT) is a resistor, it is feasible to extend this technique by placing many resistors in an IC to monitor the local temperatures, without increasing IC design complexity. This could lead to better understanding of the thermal profile of ICs at cryogenic temperatures. This has its greatest potential application in quantum computing, where the temperature at the cold classical-quantum boundary must be carefully controlled to maintain qubit performance.

physics.app-ph↗

arXiv2022

A Perception-Driven Approach To Immersive Remote Telerobotics

Virtual Reality (VR) interfaces are increasingly used as remote visualization media in telerobotics. Remote environments captured through RGB-D cameras and visualized using VR interfaces can enhance operators' situational awareness and sense of presence. However, this approach has strict requirements for the speed, throughput, and quality of the visualized 3D data.Further, telerobotics requires operators to focus on their tasks fully, requiring high perceptual and cognitive skills. This paper shows a work-in-progress framework to address these challenges by taking the human visual system (HVS) as an inspiration. Human eyes use attentional mechanisms to select and draw user engagement to a specific place from the dynamic environment. Inspired by this, the framework implements functionalities to draw users's engagement to a specific place while simultaneously reducing latency and bandwidth requirements.

cs.HC↗

arXiv1995

Long Distance Contributions to Penguin Processes $b\rightarrow sγ$ and $b\rightarrow d γ$

We consider the long distance contributions to inclusive penguin processes through processes like $b\rightarrow s V$ and $b\rightarrow d V$ where $V$ are $^3S_1(c\bar c)$ states $ψ_i$ in the former case and include $ρ$, $ω$ for the latter case. We carefully examine vector dominance for $\bar c c$ states, and conclude that there is a large suppression of $ψ\sim γ$ transition when $ψ$ is at $q^2 = 0$. The long distance effects can be at most 10\% in both the amplitudes for $b\rightarrow sγ$ and $b\rightarrow d γ$. Although the long distance contributions are small, the ratio $BR(b\rightarrow dγ)/BR(b \rightarrow s γ) = |V_{td}/V_{ts}|^2$ does not hold due to significant $u$ and $c$ loop contributions to the short distance $b\rightarrow dγ$ amplitudes .

hep-ph↗

arXiv1994

Hadronic Penguin B Decays In The Standard And The Two-Higgs-Doublet Models

We study in next-to-leading order QCD hadronic penguin $B$ decays in the Standard and two-Higgs-doublet models. Although the gluonic penguin dominates, we find the electroweak contribution non-negligible. In the Standard Model, the branching ratio for $B \rightarrow X_s ϕ$ is predicted to be in the range $(0.6\sim 2)\times 10^{-4}$. The ranges of branching ratios for $B\rightarrow K ϕ$, $B\rightarrow K^*ϕ$, and $B_s\rightarrow ϕϕ$ are $(0.4\sim 2)\times 10^{-5}$, $(0.2\sim 1)\times 10^{-5}$, and $(0.15\sim 0.5)\times 10^{-5}$, respectively. The contribution from the charged Higgs boson in two Higgs doublet models depend on $cotβ$, and can be as large as 40\%.

hep-ph↗

arXiv1994

Proton Life-Time Problem In Finite Grand Unified Theories

We study proton decay in finite supersymmetric SU(5) grand unified theories. We find that the dimension-five operators due to color triplet higgsino induce too rapid a proton decay. This behaviour can be traced to the large Yukawa couplings to the first generation that are necessary for finiteness.

hep-ph↗