Last updated: May 31st, 2024.
Although I now work in quantitative finance, my academic research still reflects key tools I bring into financial modeling, such as stochastic methods, optimization, and time-dependent dynamics.
I hold a PhD in quantum physics from the University of Houston. My research work involves conformal systems, quantum field theory, quantum information, and quantum computing education. During my last 2 years, I worked in designing materials for an undergraduate quantum computing course with support from the CMALS Graduate Fellowship.
I have experience in computational, theoretical, and experimental physics. During my master's degree projects, I gained experience in computational physics, infectious disease modeling, and application of classical optimization and machine learning algorithms. On the experimental side, I have worked in growing and characterizing novel materials for energy harvesting and thermal management.
Publications:
* Author ordering is alphabetical, which is a standard practice in theoretical physics.
[6] *P. Lopez-Duque et al. Conformal quantum mechanics of causal diamonds: Quantum instability and semiclassical approximation. Submitted. (2024)
[5] *P. Lopez-Duque et al. Conformal quantum mechanics of causal diamonds: Time evolution and thermality via path integral functionals. Submitted. (2024)
[4] P. Lopez Duque et al. Magnetization reversal phenomena in thin films presenting stripe domains. J. Phys. D: Appl. Phys. 57 365001 (2024).
[3] *P. Lopez-Duque et al. Entanglement degradation in causal diamonds, Phys. Rev. D 109, 105003 (2024).
[2] *P. Lopez-Duque et al, Spectral Properties of the Symmetry Generators Conformal Quantum Mechanics: A Path-Integral Approach. Journal of Mathematical Physics. J. Math. Phys. 64, 092302 (2023).
[1] N. Amaguayo, A. Musello, P. Lopez, L. Trojman, L. M. Procel and J. Bustamante, Fabrication of Nanopores Using the Controlled Dielectric Breakdown Technique, 2021 IEEE Latin America Electron Devices Conference, pp. 1-4 (2021).
Overview of Projects:
A finite-lifetime observer detects thermal particles in the Minkowski vacuum. Such an observer is constrained to a diamond shaped region in the flat spacetime -- known as a causal diamond. In the literature, it has been shown that the generator of the time evolution of a diamond observer is a non-compact SO(2,1) hyperbolic transformation generator S and is intimately connected to conformal quantum mechanics (CQM). In this paper, using an explicit representation of this S operator as described in the de Alfaro-Fubini-Furlan model involving the inverse square potential and the inverted harmonic oscillator potential, we explore the connection between CQM and thermality in causal diamonds via a semiclassical approach. In doing so, we probe the role of instability in determining the diamond temperature by using the Gutzwiller Trace Formula. We further make some comments about the quantum chaotic nature of the S operator.
To appear in: *P. Lopez-Duque et al. Conformal quantum mechanics of causal diamonds: Quantum instability and semiclassical approximation. Submitted (2024).
The core goal of this project was to determine if the entanglement of a Bell state of scalar field modes is affected when a finite lifetime observer measures it. As it is widely known, entanglement is the most important resources for quantum information tasks, including quantum computing. Since in practice all systems have a finite lifetime, understanding entanglement under this restriction is paramount. We showed that entanglement is indeed degraded from the finite lifetime observer perspective due to thermal effects by establishing a correspondence with the case for an accelerated observer through a conformal mapping. During this project, I learnt important concepts about quantum information and quantum computing. I also began to learn how to deploy and simulate circuits in a real computer by using IBM’s Qiskit.
Publication: *H. Camblong, A. Chakraborty, P. Lopez-Duque and C.R. Ordonez, Entanglement degradation in causal diamonds, Phys. Rev. D 109, 105003 (2024). https://arxiv.org/abs/2402.10417v1
In this project, we developed a path-integral approach to study the spectral properties of the generators of the SO(2,1) symmetry of conformal quantum mechanics (CQM). In particular, we considered the weak-coupling regime of the inverse square potential. We developed a general framework to characterize a generic symmetry generator G (linear combinations of the Hamiltonian H, special conformal operator K, and dilation operator D), from which the path-integral propagators follow, leading to a complete spectral decomposition. This is done for the three classes of operators: elliptic, parabolic, and hyperbolic. We also highlight novel results for the hyperbolic operators, with a continuous spectrum, and their quantum-mechanical interpretation. The operator in the Cartan-basis S belongs to this class and has been associated to thermal effects in causal diamonds.
Publication: * H. Camblong, A. Chakraborty, P. Lopez-Duque and C.R. Ordonez, Spectral Properties of the Symmetry Generators Conformal Quantum Mechanics: A Path-Integral Approach. J. Math. Phys. 64, 092302 (2023). https://arxiv.org/abs/2210.02370
In this project, I co-developed a computational model to quantify the role of essential workers in the transmission of the disease and the effectivity of mask and lockdown policies to slowdown infections. I simulated a compartmental model in Mathematica and Python and built applets that allow to vary different parameters related to infections, including interaction time at different spatial locations, mask policies compliance, disease’s infectivity, among others. In addition, I performed gradient descent optimization in Python to fit infection curves from real data for 3 different states in the US. We found that essential workers have a significant impact in the transmission, and that the effectivity of mask and lockdown policies depend strongly and timing, strength, and adoption.
I also co-developed a neighborhood model to analyze the transmission between communities consisting of heterogenous populations of essential and non-essential workers.
Publications:
P. Lopez-Duque, G. Morrison. A Model to Assess the Effectiveness of Lockdowns and Mask Mandates on Reducing COVID-19 Infections in Essential Worker Populations. In preparation. (2024).
P. Lopez-Duque, Assessing the Effectiveness of Lockdowns and Mask Mandates on Reducing COVID-19 Infections in Essential Worker Populations. A M.Sc. thesis submitted to the Department of Physics, University of Houston, July 2021.
In the latest study, we analyzed the magnetization reversal process in two thin film samples with magnetic stripe domains: Fe0:82Ga0:18 (Fe-Ga) and Ni0:81Fe0:19 (permalloy). We highlighted the difference in the reversal process between the two samples. In our Fe-Ga thin films, the reversal is driven by thermal activation, as revealed by the magnetic viscosity behavior. This means that the reversal process occurs gradually, with the magnetization switching direction via 10 nm-long jumps of magnetic domain walls. In the case of our permalloy samples, we showed that the measurement of the transversal magnetization component shows a much higher sensitivity for the determination of the in-plane magnetic anisotropy than the usual hysteresis loops where the magnetization is parallel to the applied field.
Publication: P. Lopez Duque, D. Goijman, A. Sarmiento, G. Ramrez, L. Aviles-Felix, J. Gomez, M. Eddrief, A. Butera, P. Vavassori, J. Milano, and D. Niebieskikwiat. Magnetization reversal phenomena in thin films presenting stripe domains. J. Phys. D: Appl. Physics. Accepted (2024).
In a previous project, we investigated the correlation between magnetic anisotropies, Gallium (Ga) concentration and magnetic properties in Fe_{1-x}Ga_x thin films, grown on a ZnSe/GaAs(001) substrate. The magnetic activation reversal volumes were calculated for films of different Ga concentration and thickness. We found a region of linear evidence of striped domains in the MH curves that appears as a result of an out of plane anisotropy. This behavior was confirmed using magnetic force microscopy. We also observed a bubble pattern when the field is applied in the out of plane direction. This is expected since there is no symmetry breaking in the plane of the sample.
Publication: P. Lopez-Duque, Magnetic Characterization of epitaxial FeGa thin films grown on ZnSe/GaAs). A B.Sc. thesis submitted to the department of Physics, Universidad San Francisco de Quito.
In this work, we constructed a system for the fabrication of a single solid-state nanopore in a membrane using controlled dielectric breakdown. This technique is becoming the main solid-state nanopore fabrication technique worldwide. We developed a building process consisting of mainly low-cost equipment for nanopore fabrication, and provide a guide for building a similar system where economical resources are scarce. We used the system to create two nanopores, which were later characterized to show the feasibility of our approach.
Publication: N. Amaguayo, A. Musello, P. Lopez, L. Trojman, L. M. Procel and J. Bustamante, "Fabrication of Nanopores Using the Controlled Dielectric Breakdown Technique," 2021 IEEE Latin America Electron Devices Conference (LAEDC), 2021, pp. 1-4.
Using chemical vapor transport, we synthesized boron arsenide (BAs) single cristals with high thermal conductity and high electron mobility. I characterized the material using XRD spectroscopy and a scanning electron microscope (SEM).
I also studied the feasibility of using BAs single crystals towards application of the material to design a PV cell and presented results showing that crystal quality should be improved.