@inproceedings {675,
	title = {Implementation of a quantum Otto thermal machine using an XX spin chain model},
	booktitle = {Proceedings of the 42nd Samahang Pisika ng Pilipinas Physics Conference},
	year = {2024},
	month = {3{\textendash}6 Jul 2024},
	pages = {SPP-2024-PC-12},
	address = {Batangas City},
	abstract = {Quantum thermal machine models are essential to understanding the thermodynamics of nanoscale systems. A quantum Otto thermal machine with a spin XX chain working substance was considered. The different working regimes was demonstrated for a chain of 10 spins by calculating the work and heat absorbed for one cycle. It was found that at high bath temperatures, the quantum Otto engine mainly operates as either accelerator or a heat engine, while at low bath temperatures it operates mainly as a heater. Additionally, sinusoidal fluctuations in the heat and work plots are more apparent at low bath temperatures. This is presumably attributed to the low dimension of the system, which dissappears in the thermodynamic limit. These findings are precursor to optimal device design using Otto engines based on the spin XX chain model.},
	url = {https://proceedings.spp-online.org/article/view/SPP-2024-PC-12},
	author = {Geronimo Allan Jerome Acosta and Cristine D. Villagonzalo}
}
@conference {645,
	title = {Enhanced efficiency of a quantum Otto engine based on an XX spin chain near its dynamical phase transition},
	year = {2023},
	month = {6{\textendash}10 Nov 2023},
	pages = {P.26},
	publisher = {Asian Network School and Workshop on Complex Condensed Matter Systems 2023},
	address = {IOP VAST, Vietnam},
	abstract = {Implementation of heat engines in the nanoscale must consider quantum effects. In this study, a quantum Otto engine with an XX spin chain as a working substance was investigated near its dynamical phase transition for its efficiency enhancement. We used two isothermal and two isomagnetic branches for the thermodynamic cycle of the quantum Otto engine. The working substance was operated at the ground state and at a thermal state. The isothermal branches were implemented at zero temperature and inverse temperature βJ >= 1, while the isomagnetic branches at constant  |λ/J| < 2. The quantum heat engine was found to achieve a 100\% peak efficiency near the ground state curve in the chemical potential diagram and operates at constant 100\% efficiency for extended regions when the system undergoes dynamical phase transition.},
	url = {https://iop.vast.vn/asian/2023/program.php?t=1\&n=26},
	author = {Geronimo Allan Jerome Acosta and Cristine D. Villagonzalo}
}
@inproceedings {acostaSPP2019,
	title = {Current amplification and rectification in a chain of four spins individually coupled to different heat baths},
	booktitle = {Proceedings of the 37th Samahang Pisika ng Pilipinas Physics Conference},
	year = {2019},
	month = {29 May 2019},
	pages = {SPP-2019-PB-33},
	address = {Tagbilaran City, Philippines},
	abstract = {In this work, we considered a linear chain consisting of four spins individually coupled to different heat baths. We calculated numerically the heat currents by solving the transition rate equations as previously discussed in Ref. [1]. The temperature of the heat bath of the first spin is held constant. The temperatures of the second and third heat baths are set to be the average of the heat baths at the edges while the temperature of the fourth heat bath at the edge is allowed to vary from zero to twice the temperature of the first heat bath. We demonstrate that for a chain of spins conjugate to this heat bath temperature configuration, current amplification and rectification are exhibited.},
	url = {https://paperview.spp-online.org/proceedings/article/view/SPP-2019-PB-33},
	author = {Geronimo Allan Jerome Acosta and Cristine Villagonzalo}
}
@inproceedings {acosta,
	title = {Derivation of heat transport equations for a chain of four interacting spins individually coupled to different heat baths},
	booktitle = {Proceedings of the 35th Samahang Pisika ng Pilipinas Physics Conference},
	year = {2017},
	month = {7{\textendash}10 June 2017},
	pages = {SPP-2017-PB-02},
	address = {Cebu City, Philippines},
	abstract = {In this work we considered a linear chain consisting of four (4) spins individually coupled to different heat baths. For this configuration, we used the quantum master equation to derive the heat currents in terms of transition rates. We obtain a set of linear equations that can be solved explicitly to get the transition rates.},
	url = {http://paperview.spp-online.org/proceedings/article/view/42},
	author = {Geronimo Allan Jerome Acosta and Cristine Villagonzalo}
}