arXiv subjects

Param Patel

Publications and source records attributed to Param Patel.

3 recordsLinked to original sources

arXiv2026

A Vendor-Agnostic LiDAR Data Conversion System with Multi-Signal Detection and Multi-Format Output

LiDAR (Light Detection and Ranging) sensors capture the surrounding environment as dense 3D point clouds by measuring the time-of-flight of emitted laser pulses, making them foundational across autonomous vehicles, robotics, and large-scale mapping. PCAP (Packet Capture) files from these sensors are the starting point of most 3D perception pipelines, yet internal packet structures, UDP (User Datagram Protocol) port conventions and encoding schemes differ enough across manufacturers that no single tool reads them all. Ouster, Velodyne, Hesai, and Livox each require their own SDK (Software Development Kit), their own environment setup, and their own conversion workflow. Supporting all four means maintaining four disconnected pipelines with no shared infrastructure. The pipeline described here takes a raw PCAP as input and handles vendor identification automatically, scoring six independent file characteristics through a weighted multi-signal approach to determine the source sensor. C++ SDKs handle Ouster and Velodyne, while Hesai and Livox rely on Python-based dpkt parsing where no open source SDK exists. From there, a single command writes output to any of five industry-standard formats. We tested on real outdoor captures. Ouster peaks at 2.08M points per second, Velodyne at 1.47M, both running through native C++ packet decoding. Hesai and Livox land at 110K and 150K respectively, where Python-layer parsing introduces overhead that compounds under sustained load. The 8-10x gap held consistently across runs. Tested on a consumer-grade i3 with 8GB RAM, no vendor configuration required

cs.RO↗

arXiv2025

The waves-in-space Purcell effect for superconducting qubits

Quantum information processing, especially with quantum error correction, requires both long-lived qubits and fast, quantum non-demolition readout. In superconducting circuits this leads to the requirement to both strongly couple qubits, such as transmons, to readout modes while also protecting them from associated Purcell decay through the readout port. So-called Purcell filters can provide this protection, at the cost of significant increases in circuit components and complexity. However, as we demonstrate in this work, visualizing the qubit fields in space reveals locations where the qubit fields are strong and cavity fields weak; simply placing ports at these locations provides intrinsic Purcell protection. For a $\lambda/2$ readout mode in the `chip-in-tube' geometry, we show both millisecond level Purcell protection and, conversely, greatly enhanced Purcell decay (qubit lifetime of 1~$\mu$s) simply by relocating the readout port. This method of integrating the Purcell protection into the qubit-cavity geometry can be generalized to other 3D implementations, such as post-cavities, as well as planar geometries. For qubit frequencies below the readout mode this effect is quite distinct from the multi-mode Purcell effect, which we demonstrate in a 3D-post geometry where we show both Purcell protection of the qubit while spoiling the quality factor of higher cavity harmonics to protect against dephasing due to stray photons in these modes.

quant-ph↗

arXiv2023

Fast superconducting qubit control with sub-harmonic drives

Increasing the fidelity of single-qubit gates requires a combination of faster pulses and increased qubit coherence. However, with resonant qubit drive via a capacitively coupled port, these two objectives are mutually contradictory, as higher qubit quality factor requires a weaker coupling, necessitating longer pulses for the same applied power. Increasing drive power, on the other hand, can heat the qubit's environment and degrade coherence. In this work, by using the inherent nonlinearity of the transmon qubit, we circumvent this issue by introducing a new parametric driving scheme to perform single-qubit control. We achieve rapid gate speed by pumping the transmon's native Kerr term at approximately one third of the qubit's resonant frequency. Given that transmons typically operate within a fairly narrow range of anharmonicity, this technique is applicable to all transmons. In both theory and experiment, we show that the Rabi rate of the process is proportional to applied drive amplitude cubed, allowing for rapid gate speed with only modest increases in applied power. In addition, we demonstrate that filtering can be used to protect the qubit's coherence while performing rapid gates, and present theoretical calculations indicating that decay due to multi-photon losses, even in very strongly coupled drive lines, will not limit qubit lifetime. We demonstrate single qubit gates as short as 37.4ns with fidelity as high as 99.91%. We also present calculations indicating that this technique could reduce cryostat heating for fast gates, a vital requirement for large-scale quantum computers.

quant-ph↗