Karpat, Göktuğ
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Karpat, G
Karpat, Göktug
Karpat, Goktug
Karpat, G.
Karpat, Göktug
Karpat, Goktug
Karpat, G.
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Email Address
goktug.karpat@ieu.edu.tr
Main Affiliation
02.03. Physics
Status
Former Staff
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WoS Researcher ID
Sustainable Development Goals
SDG data is not available
Documents
36
Citations
1290
h-index
18
Documents
36
Citations
1296
Scholarly Output
16
Articles
14
Views / Downloads
2/33
Supervised MSc Theses
0
Supervised PhD Theses
0
WoS Citation Count
185
Scopus Citation Count
190
Patents
0
Projects
2
WoS Citations per Publication
11.56
Scopus Citations per Publication
11.88
Open Access Source
15
Supervised Theses
0
| Journal | Count |
|---|---|
| Physıcal Revıew A | 6 |
| Entropy | 2 |
| Canadıan Journal of Physıcs | 2 |
| Physical Review A | 2 |
| Quantum Informatıon Processıng | 2 |
Current Page: 1 / 2
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16 results
Scholarly Output Search Results
Now showing 1 - 10 of 16
Article Citation - WoS: 3Citation - Scopus: 3Remote Polarization-Entanglement Generation by Local Dephasing and Frequency Up-Conversion(Amer Physical Soc, 2017) Raja, S. Hamedani; Karpat, G.; Laine, E. -M.; Maniscalco, S.; Piilo, J.; Li, C. -F.; Guo, G. -C.We introduce a scheme for remote entanglement generation for the photon polarization. The technique is based on transferring the initial frequency correlations to specific polarization-frequency correlations by local dephasing and their subsequent removal by frequency up-conversion. On fundamental level, our theoretical results show how to create and transfer entanglement, to particles which never interact, by means of local operations. This possibility stems from the multipath interference and its control in frequency space. For applications, the developed techniques and results allow for the remote generation of entanglement with distant parties without Bell state measurements and open the perspective to probe frequency-frequency entanglement by measuring the polarization state of the photons.Article Citation - WoS: 3Citation - Scopus: 3Time-Invariant Discord: High Temperature Limit and Initial Environmental Correlations(Springer, 2018) Tabesh, F. T.; Karpat, G.; Maniscalco, S.; Salimi, S.; Khorashad, A. S.We present a thorough investigation of the phenomena of frozen and time-invariant quantum discord for two-qubit systems independently interacting with local reservoirs. Our work takes into account several significant effects present in decoherence models, which have not been yet explored in the context of time-invariant quantum discord, but which in fact must be typically considered in almost all realistic models. Firstly, we study the combined influence of dephasing, dissipation and heating reservoirs at finite temperature. Contrarily to previous claims in the literature, we show the existence of time-invariant discord at high temperature limit in the weak coupling regime and also examine the effect of thermal photons on the dynamical behavior of frozen discord. Secondly, we explore the consequences of having initial correlations between the dephasing reservoirs. We demonstrate in detail how the time-invariant discord is modified depending on the relevant system parameters such as the strength of the initial amount of entanglement between the reservoirs.Article Citation - WoS: 25Citation - Scopus: 27Synchronization and Non-Markovianity in Open Quantum Systems(Amer Physical Soc, 2021) Karpat, Goktug; Yalcinkaya, Iskender; Cakmak, Baris; Luca Giorgi, Gian; Zambrini, Roberta; Giorgi, Gian LucaY Detuned systems can spontaneously achieve a synchronous dynamics and display robust quantum correlations in different local and global dissipation regimes. Beyond the Markovian limit, information backflow from the environment becomes a crucial mechanism whose interplay with spontaneous synchronization is unknown. Considering a model of two coupled qubits, one of which interacts with a dissipative environment, we show that non-Markovianity is highly detrimental for the emergence of synchronization, for the latter can be delayed and hindered because of the presence of information backflow. The results are obtained considering both a master equation approach and a collision model based on repeated interactions, which represents a very versatile tool to tailor the desired kind of environment.Article Citation - WoS: 21Citation - Scopus: 23Estimating the Degree of Non-Markovianity Using Machine Learning(Amer Physical Soc, 2021) Fanchini, Felipe F.; Karpat, Goktug; Rossatto, Daniel Z.; Norambuena, Ariel; Coto, RaulIn the last few years, the application of machine learning methods has become increasingly relevant in different fields of physics. One of the most significant subjects in the theory of open quantum systems is the study of the characterization of non-Markovian memory effects that emerge dynamically throughout the time evolution of open systems as they interact with their surrounding environment. Here we consider two well-established quantifiers of the degree of memory effects, namely, the trace distance and the entanglement-based measures of non-Markovianity. We demonstrate that using machine learning techniques, in particular, support vector machine algorithms, it is possible to estimate the degree of non-Markovianity in two paradigmatic open system models with high precision. Our approach can be experimentally feasible to estimate the degree of non-Markovianity, since it requires a single or at most two rounds of state tomography.Article Entropy Production in Non-Markovian Collision Models: Information Backflow vs. System-Environment Correlations(MDPI, 2022) Çakmak, Barış; Karpat, Göktuğ; Şenyaşa, Hüseyin T.; Kesgin, ŞahindeArticle Citation - WoS: 39Citation - Scopus: 39Quantum Synchronization in a Collision Model(Amer Physical Soc, 2019) Karpat, G.; Yalcinkaya, I; Cakmak, B.We reveal the emergence of environment-induced spontaneous synchronization between two spin-1/2 quantum objects in a collision model setting. In particular, we determine the conditions for the dynamical establishment of synchronous evolution between local spin observables of a pair of spins undergoing open-system dynamics in the absence of an external drive. Exploiting the versatility of the collision model framework, we show that the formation of quantum or classical correlations between the principal spin pair is of no significant relevance to the manifestation of spontaneous quantum synchronization between them. Furthermore, we discuss the consequences of thermal effects on the environmental spins for the emergence of quantum synchronization.Article Citation - WoS: 4Citation - Scopus: 3Symmetry in the Open-System Dynamics of Quantum Correlations(Nature Publishing Group, 2017) Lyyra, Henri; Karpat, Goktug; Li, Chuan-Feng; Guo, Guang-Can; Piilo, Jyrki; Maniscalco, SabrinaWe study the symmetry properties in the dynamics of quantum correlations for two-qubit systems in one-sided noisy channels, with respect to a switch in the location of noise from one qubit to the other. We consider four different channel types, namely depolarizing, amplitude damping, bit-flip, and bit-phase-flip channel, and identify the classes of initial states leading to symmetric decay of entanglement, non-locality and discord. Our results show that the symmetric decay of quantum correlations is not directly linked to the presence or absence of symmetry in the initial state, while it does depend on the type of correlation considered as well as on the type of noise. We prove that asymmetric decay can be used to infer, in certain cases, characteristic properties of the channel. We also show that the location of noise may lead to dramatic changes in the persistence of phenomena such as entanglement sudden death and time-invariant discord.Article Citation - WoS: 13Citation - Scopus: 13Disorder-Free Localization in Quantum Walks(Amer Physical Soc, 2021) Danaci, B.; Yalcinkaya, I; Cakmak, B.; Karpat, G.; Kelly, S. P.; Subasi, A. L.; Yalçınkaya, İ.; Danacı, B.; Subaşı, A.L.The phenomenon of localization usually happens due to the existence of disorder in a medium. Nevertheless, certain quantum systems allow dynamical localization solely due to the nature of internal interactions. We study a discrete time quantum walker which exhibits disorder-free localization. The quantum walker moves on a one-dimensional lattice and interacts with on-site spins by coherently rotating them around a given axis at each step. Since the spins do not have dynamics of their own, the system poses the local spin components along the rotation axis as an extensive number of conserved moments. When the interaction is weak, the spread of the walker shows subdiffusive behavior having downscaled ballistic tails in the evolving probability distribution at intermediate timescales. However, as the interaction gets stronger the walker gets completely localized in total absence of disorder in both lattice and initial state. Using a matrix-product-state ansatz, we investigate the relaxation and entanglement dynamics of the on-site spins due to their coupling with the quantum walker. Surprisingly, we find that, even in the delocalized regime, entanglement growth and relaxation occur slowly, unlike majority of the other models displaying a localization transition.Conference Object Citation - WoS: 2Citation - Scopus: 2Invariant Entanglement and Generation of Quantum Correlations Under Global Dephasing(Canadian Science Publishing, Nrc Research Press, 2018) Karpat, GoktugWe investigate the dynamics of quantum entanglement and more general quantum correlations quantified via negativity and local quantum uncertainty, respectively, for two-qubit systems undergoing Markovian collective dephasing. Focusing on a two-parameter family of initial two-qubit density matrices, we study the relation of the emergence of the curious phenomenon of time-invariant entanglement and the dynamical behavior of local quantum uncertainty. Developing an illustrative geometric approach, we demonstrate the existence of distinct regions of quantum entanglement for the considered initial states and identify the region that allows for completely frozen entanglement throughout the dynamics, accompanied by generation of local quantum uncertainty. Furthermore, we present a systematic analysis of different dynamical behaviors of local quantum uncertainty, such as its sudden change or smooth amplification, in relation with the dynamics of entanglement.Article Citation - WoS: 2Citation - Scopus: 2Predicting the Onset of Quantum Synchronization Using Machine Learning(American Physical Society, 2024) Mahlow, F.; Çakmak, B.; Karpat, G.; Yalçlnkaya, I.; Fanchini, F.F.; Yalcinkaya, I.We have applied a machine learning algorithm to predict the emergence of environment-induced spontaneous synchronization between two qubits in an open system setting. In particular, we have considered three different models, encompassing global and local dissipation regimes, to describe the open system dynamics of the qubits. We have utilized the k-nearest-neighbor algorithm to estimate the long-time synchronization behavior of the qubits only using the early time expectation values of qubit observables in these three distinct models. Our findings clearly demonstrate the possibility of determining the occurrence of different synchronization phenomena with high precision even at the early stages of the dynamics using a machine learning-based approach. Moreover, we show the robustness of our approach against potential measurement errors in experiments by considering random errors in the qubit expectation values, initialization errors, as well as deviations in the environment temperature. We believe that the presented results can prove to be useful in experimental studies on the determination of quantum synchronization. © 2024 American Physical Society.
