arXiv subjects

Ping Zheng

Publications and source records attributed to Ping Zheng.

7 recordsLinked to original sources

arXiv2026

AIPOCH Open-Science: An Open-Source AI Research Workbench with Reproducible .science Packages

AI-assisted research leaves instructions, computations, artifact revisions and checks whose relationships matter when another researcher receives the work. We present AIPOCH Open-Science, an open-source research workbench with portable .science session packages, and specify an exchange contract for these recorded relationships. Version and assessment targets remain attributable while receiving-workspace identifiers can be remapped, eligible contents can be omitted explicitly, and imported history remains separate from a writable fork. A controlled session tested an incorrect first version, a reviewed correction, an unreviewed revision and a planned but unexecuted step. We compared complete and partial exports with source records extracted independently of the exporter, then inspected imports into separate projects within the same installation. Both conditions retained the tested version and review associations, kept the unreviewed revision distinct from earlier assessments and represented excluded content as unavailable. A documentation-rich ordinary directory also supplied evidence for all seven static inspection questions. A separate registry case connected a table to its recorded task, execution and review; offline execution of its retained script and fixed input reproduced two saved CSV tables byte for byte. The study contributes an implemented exchange contract and a controlled examination of its preservation rules, content-selection constraints and interpretation boundaries.

cs.SE↗

arXiv2026

Agent-Warden: eBPF-Based Kernel-Native Process-File Provenance Tracking for LLM Agents

LLM agents execute dynamically generated process and file operations that are often invisible to application-layer tracing. We present Agent-Warden, an extended Berkeley Packet Filter (eBPF)-based provenance monitor for tracking task and regular-file states across process creation, file access, and process termination. Agent-Warden provides two interchangeable state backends: a PID-keyed hash-map backend for compatible kernels lacking BPF local-storage support and a task/inode-local-storage backend that couples state reclamation to kernel-object lifetimes. The system emits incremental causal edges to user space for asynchronous graph reconstruction and applies conservative exit-triggered causal aggregation to preserve causal context for short-lived proxy tasks. In a controlled file-mediated propagation scenario, Agent-Warden reconstructed a cross-process causal chain that was absent from the application-layer trace. On x86-64 and ARM64 bare-metal hosts, the evaluated workloads showed 0.2-3.5% end-to-end overhead and 0.6-3.7% additional system CPU time. These results indicate that the prototype provides kernel-level visibility with the measured overheads in the evaluated settings.

cs.CR↗

arXiv2026

ContractWarden: Kernel-Enforced Damage Boundaries for AI Agents via Human-Authorized Contracts

Large language model agents can execute commands, create subprocesses, and directly access files and networks, allowing prompt injection or planning errors to become operating-system side effects. We present ContractWarden, a Linux reference monitor that enforces a human-authorized damage boundary without trusting the agent or its policy suggestions. A model may propose a tri-state asset contract - allow, deny, or no_egress - but a human makes the final choice. An execution gate binds the contract to a concrete task before untrusted code runs. An extended Berkeley Packet Filter (eBPF) Linux Security Modules (LSM) data plane then enforces file and network decisions and monotonically propagates no_egress through processes, regular files, pipes, FIFOs, and supported Unix-domain sockets. All 570 runs across 19 security tests satisfy predefined return-value and side-effect criteria. On three co-located file-I/O workloads, median overhead is 11.96-12.89% in a Linux 6.15 virtual machine and 35.79-61.54% on a Linux 6.15 physical platform, lower than the evaluated frozen ActPlane baseline. The results demonstrate deterministic kernel enforcement for declared assets, supported paths, and controlled object lifecycles.

cs.CR↗

arXiv2021

Tri-Hexagonal charge order in kagome metal CsV$_{3}$Sb$_{5}$ revealed by $^{121}$Sb NQR

We report $^{121}$Sb nuclear quadrupole resonance (NQR) measurements on kagome superconductor CsV$_3$Sb$_5$ with $T_{\rm c}=2.5$ K. $^{121}$Sb NQR spectra split after a charge density wave (CDW) transition at $94$ K, which demonstrates a commensurate CDW state. The coexistence of the high temperature phase and the CDW phase between $91$ K and $94$ K manifests that it is a first order phase transition. The CDW order exhibits Tri-Hexagonal deformation with a lateral shift between the adjacent kagome layers, which is consistent with $2 \times 2 \times 2$ superlattice modulation. The superconducting state coexists with CDW order and shows a conventional s-wave behavior in the bulk state.

cond-mat.str-el↗

arXiv2017

First-principles calculations of the magnetic and electronic structures of MnP under pressure

Manganese monophosphide (MnP) shows complicated magnetic states varying with both temperature and pressure. We calculate the magnetic and electronic structures of MnP at different pressures using first-principles methods and obtain spiral ground states whose propagation vector changes from the c-axis at low pressure to the b-axis at high pressure. In between, we find a ferromagnetic state, as observed in the experimental phase diagram. The propagation vector of the spiral states is found to vary nonmonotonically with pressure, consistent with neutron measurements. Our results indicate that the complicated magnetic phase diagram originates from a delicate competition between neighboring exchange interactions between the Mn-ions. At all pressures, the electronic structures indicate the existence of quasi-one-dimensional charge carriers, which appear in the ferromagnetic state and become gapped in the spiral state, and anisotropic three-dimensional charge carriers. We argue that this two-fluid behavior originates from the special crystal structure of MnP and may be relevant for understanding the pairing mechanism of the superconductivity at the border of the high pressure spiral phase.

cond-mat.supr-con↗

arXiv2015

(Li0.84Fe0.16)OHFe0.98Se superconductor: Ion-exchange synthesis of large single crystal and highly two-dimensional electron properties

A large and high-quality single crystal (Li0.84Fe0.16)OHFe0.98Se, the optimal superconductor of newly reported (Li1-xFex)OHFe1-ySe system, has been successfully synthesized via a hydrothermal ion-exchange technique. The superconducting transition temperature (Tc) of 42 K is determined by magnetic susceptibility and electric resistivity measurements, and the zero-temperature upper critical magnetic fields are evaluated as 79 and 313 Tesla for the field along the c-axis and the ab-plane, respectively. The ratio of out-of-plane to in-plane electric resistivity,\r{ho}c/\r{ho}ab, is found to increases with decreasing temperature and to reach a high value of 2500 at 50 K, with an evident kink occurring at a characteristic temperature T*=120 K. The negative in-plane Hall coefficient indicates that electron carriers dominate in the charge transport, and the hole contribution is significantly reduced as the temperature is lowered to approach T*. From T* down to Tc, we observe the linear temperature dependences of the in-plane electric resistivity and the magnetic susceptibility for the FeSe layers. Our findings thus reveal that the normal state of (Li0.84Fe0.16)OHFe0.98Se becomes highly two-dimensional and anomalous prior to the superconducting transition, providing a new insight into the mechanism of high-Tc superconductivity.

cond-mat.supr-con↗

arXiv2012

Strong-Coupling Superconductivity in NaFe$_{1-x}$Co$_x$As: the Eliashberg Theory and Beyond

We study the normal-state and superconducting properties of NaFe$_{1-x}$Co$_x$As system by specific heat measurements. Both the normal-state Sommerfeld coefficient and superconducting condensation energy are strongly suppressed in the underdoped and heavily overdoped samples. The low-temperature electronic specific heat can be well fitted by either an one-gap or a two-gap BCS-type function for all the superconducting samples. The ratio $γ_NT_c^2/H_c^2(0)$ can nicely associate the neutron spin resonance as the bosons in the standard Eliashberg model. However, the value of $ΔC/T_cγ_N$ near optimal doping is larger than the maximum value the model can obtain. Our results suggest that the high-$T_c$ superconductivity in the Fe-based superconductors may be understood within the framework of boson-exchange mechanism but significant modification may be needed to account for the finite-temperature properties.

cond-mat.supr-con↗