arXiv subjects

Fakhar Zaman

Publications and source records attributed to Fakhar Zaman.

5 recordsLinked to original sources

arXiv2025

Quantum Down Sampling Filter for Variational Auto-encoder

Variational autoencoders (VAEs) are fundamental for generative modeling and image reconstruction, yet their performance often struggles to maintain high fidelity in reconstructions. This study introduces a hybrid model, quantum variational autoencoder (Q-VAE), which integrates quantum encoding within the encoder while utilizing fully connected layers to extract meaningful representations. The decoder uses transposed convolution layers for up-sampling. The Q-VAE is evaluated against the classical VAE and the classical direct-passing VAE, which utilizes windowed pooling filters. Results on the MNIST and USPS datasets demonstrate that Q-VAE consistently outperforms classical approaches, achieving lower Fréchet inception distance scores, thereby indicating superior image fidelity and enhanced reconstruction quality. These findings highlight the potential of Q-VAE for high-quality synthetic data generation and improved image reconstruction in generative models.

cs.CV↗

arXiv2021

Counterfactual Full-Duplex Communication

This paper proposes two new full-duplex quantum communication protocols to exchange classical or quantum information between two remote parties simultaneously without transferring a physical particle over the quantum channel. The first protocol, called quantum duplex coding, enables to exchange of a classical bit using a preshared maximally entangled pair of qubits by means of counterfactual disentanglement. The second protocol, called quantum telexchanging, enables to exchange an arbitrary unknown qubit without using preshared entanglement by means of counterfactual entanglement and disentanglement. We demonstrate the quantum duplex coding and quantum telexchanging by exploiting counterfactual electron-photon interaction gates and show that these quantum duplex communication protocols form full-duplex binary erasure channel and quantum erasure channels, respectively.

quant-ph↗

arXiv2021

Counterfactual Concealed Telecomputation

Distributed computing is a fastest growing field -- enabling virtual computing, parallel computing, and distributed storage. By exploiting the counterfactual techniques, we devise a distributed blind quantum computation protocol to perform a universal two-qubit controlled unitary operation for any input state without using preshared entanglement and without exchanging physical particles between remote parties. This distributed protocol allows Bob to counterfactully apply an arbitrary unitary operator to Alice's qubit in probabilistic fashion, without revealing the operator to her, using a control qubit -- called the counterfactual concealed telecomputation (CCT). It is shown that the protocol is valid for general input states and that single-qubit unitary teleportation is a special case of CCT. The quantum circuit for CCT can be implemented using the (chained) quantum Zeno gates and the protocol becomes deterministic with simplified circuit implementation if the initial composite state of Alice and Bob is a Bell-type state.

quant-ph↗

arXiv2021

Information Carrier and Resource Optimization of Counterfactual Quantum Communication

Counterfactual quantum communication is unique in its own way that allows remote parties to transfer information without sending any message carrier in the channel. Although no message carrier travels in the channel at the time of successful information transmission, it is impossible to transmit information faster than the speed of light, thus without an information carrier. In this paper, we address an important question What carries the information in counterfactual quantum communication? and optimize the resource efficiency of the counterfactual quantum communication in terms of the number of channels used, time consumed to transmit 1-bit classical information between two remote parties, and the number of qubits required to accomplish the counterfactual quantum communication.

quant-ph↗

arXiv2019

Dual Quantum Zeno Superdense Coding

Quantum superdense coding enables a sender to encode a two-bit classical message in one qubit using the preshared entanglement. In this paper, we develop a superdense coding protocol using a dual quantum Zeno (DQZ) gate to take the full advantage of quantum superdense coding from the complete Bell-state analysis. We verify that the DQZ gate allows remote parties to achieve the distinguishability of orthonormal Bell states in a semi-counterfactual manner and the DQZ superdense coding achieves high throughput efficiency as a function of cycle numbers for the Bell-state analyzer.

quant-ph↗