394 citations · 458 across the 11 of their papers we have counts for
12 papers
Imaginarity as a necessary resource for trainability in QAOA
Syed Muhammad Ali Hassan, Kostas Blekos, Stefan Kühn +2
The quantum approximate optimization algorithm (QAOA) tackles combinatorial problems by tuning a quantum circuit in a classical loop, often guided by gradients. We show that the gr…
What does measuring one qubit reveal about another? -networks as a directed diagnostic for quantum circuits
Kostas Blekos, Paulo Vitor Itaboraí
Many-qubit circuit states are hard to inspect directly, so they are often summarized by pairwise graph weights. Common pairwise weights report symmetric correlations, while many ci…
Processing through encoding: Quantum circuit approaches for point-wise multiplication and convolution
Andreas Papageorgiou, Paulo Vitor Itaborai, Kostas Blekos +1
This paper introduces quantum circuit methodologies for pointwise multiplication and convolution of complex functions, conceptualized as "processing through encoding". Leveraging k…
Realizing string breaking dynamics in a lattice gauge theory on quantum hardware
Constantia Alexandrou, Andreas Athenodorou, Kostas Blekos +2
We investigate static and dynamical aspects of string breaking in a lattice gauge theory coupled to Kogut-Susskind staggered fermions. Using Tensor Network simulations, we de…
A Review on Quantum Approximate Optimization Algorithm and its Variants
Kostas Blekos, Dean Brand, Andrea Ceschini +4
The Quantum Approximate Optimization Algorithm (QAOA) is a highly promising variational quantum algorithm that aims to solve combinatorial optimization problems that are classicall…
Quantum Data Reduction with Application to Video Classification
Kostas Blekos, Dimitrios Kosmopoulos
We investigate a quantum video classification method using a hybrid algorithm. A quantum-classical step performs a data reduction on the video dataset and a quantum step -- which o…
Efficient automated U-Net based tree crown delineation using UAV multi-spectral imagery on embedded devices
Kostas Blekos, Stavros Nousias, Aris S Lalos
Delineation approaches provide significant benefits to various domains, including agriculture, environmental and natural disasters monitoring. Most of the work in the literature ut…
Performance of superadiabatic stimulated Raman adiabatic passage in the presence of dissipation and Ornstein-Uhlenbeck dephasing
Kostas Blekos, Dionisis Stefanatos, Emmanuel Paspalakis
In this paper we evaluate the performance of two superadiabatic stimulated Raman adiabatic passage (STIRAP) protocols derived from Gaussian and sin-cos pulses, under dissipation an…
Field assisted extraction and swelling of quantum coherence for moving Unruh-DeWitt detectors
Nikolaos K. Kollas, Dimitris Moustos, Kostas Blekos
We study the effects of motion for an Unruh-DeWitt detector, modeled as a two-level system, on the amount of coherence extracted, when it interacts with a massless scalar coherent…
Faithful extraction of quantum coherence
Nikolaos K. Kollas, Kostas Blekos
Coherence, a strictly quantum phenomenon, has found many applications, from quantum information theory and thermodynamics to quantum foundations and biology. When physical constrai…
Generation of maximally entangled states in hybrid two quantum dots mediated by a spherical metal nanoparticle driven by external laser field
Kostas Blekos, Maria-Eftaxia Stasinou, Andreas F. Terzis +1
We theoretically study the generation of quantum correlations in a hybrid system composed by two interacting semiconductor quantum dots mediated by a metal nanoparticle and coupled…
Polarization-entangled photon generation by a semiconductor quantum dot coupled to a cavity interacting with external fields
Kostas Blekos, Nikos Iliopoulos, Maria-Eftaksia Stasinou +2
We theoretically investigate polarization-entangled photon generation by using a semiconductor quantum dot embedded in a microcavity. The entangled states can be produced by the ap…