@phdthesis{GursesThesis2026,author={Gurses, Volkan},title={Information technologies at the fundamental physical limits},school={California Institute of Technology},month=apr,year={2026},doi={10.7907/qhb7-ew96},}
The Holevo limit bounds the channel capacity of a communication channel in which information is encoded in quantum states in a Hilbert space at the transmitter and decoded using quantum measurements at the receiver. Saturating the Holevo limit requires quantum-limited transceivers that either generate quantum states of light or employ quantum-limited measurements. Here, we demonstrate an integrated photonic-electronic quantum-limited coherent receiver (QRX) achieving 14.0 dB shot noise clearance (SNC), 520 μW knee power, 2.57 GHz 3-dB bandwidth, 3.50 GHz shot-noise-limited bandwidth, and 90.2 dB common-mode rejection ratio (CMRR). We scale this design to a 32-channel QRX array with median 26.6 dB SNC, and automatic CMRR correction yielding a median 76.8 dB CMRR at minimum. Using the integrated QRX and fiber-optic transmitter, we measure 0.15 ± 0.01 dB of squeezing below the shot noise limit, limited by off-chip losses. We propose a squeezed light communication scheme that can surpass the Shannon limit, with a path toward the Holevo limit.
@article{QCT2026,author={Gurses, Volkan and Samaga, Suraj and Kondylis, Elianna and Hajimiri, Ali},title={Quantum coherent transceivers toward Holevo-limited communications},year={2026},month=apr,url={https://arxiv.org/abs/2604.07087},doi={10.48550/arXiv.2604.07087},}
2025
NatComm
An on-chip phased array for non-classical light
Volkan Gurses, Samantha I. Davis, Raju Valivarthi, and 3 more authors
Quantum science and technology can offer fundamental enhancements in sensing, communications and computing. The expansion from wired to wireless links is an exciting prospect for quantum technologies. For classical technologies, the advent of phased arrays enabled directional and adaptive wireless links by manipulating electromagnetic waves over free space. Here we demonstrate a phased array system on a chip that can receive, image and manipulate non-classical light over free space. We use an integrated photonic-electronic system with more than 1000 functional components on-chip to detect squeezed light. By integrating an array of 32 sub-wavelength engineered metamaterial antennas, we demonstrate a direct free-space-to-chip interface for reconfigurable quantum links. On the same chip, we implement a large-scale array of quantum-limited coherent receivers that can resolve non-classical signals simultaneously across 32 channels. With coherent readout and manipulation of these signals, we demonstrate 32-pixel imaging and spatially configurable reception of squeezed light over free space. Our work advances wireless quantum technologies that could enable practical applications in quantum communications and sensing.
@article{NatComm2025,author={Gurses, Volkan and Davis, Samantha I. and Valivarthi, Raju and Sinclair, Neil and Spiropulu, Maria and Hajimiri, Ali},journal={Nature Communications},title={An on-chip phased array for non-classical light},month=jul,year={2025},volume={16},number={6849},doi={10.1038/s41467-025-61886-9},dimensions={true},}
An integrated quantum phased array receiver system in silicon photonics
Volkan Gurses, Samantha Davis, Raju Valivarthi, and 3 more authors
In Conference on Lasers and Electro-Optics (CLEO) 2025, May 2025
Emerging technologies that employ quantum physics offer fundamental enhancements in information processing tasks, including sensing, communications, and computing. Here, we introduce the quantum phased array, which generalizes the operating principles of phased arrays and wavefront engineering to quantum fields, and report the first quantum phased array technology demonstration. An integrated photonic-electronic system is used to manipulate free-space quantum information to establish reconfigurable wireless quantum links in a standalone, compact form factor. Such a robust, scalable, and integrated quantum platform can enable broad deployment of quantum technologies with high connectivity, potentially expanding their use cases to real-world applications. We report the first, to our knowledge, free-space-to-chip interface for quantum links, enabled by 32 metamaterial antennas with more than 500,000 sub-wavelength engineered nanophotonic elements over a 550 × 550 μm² physical aperture. We implement a 32-channel array of quantum coherent receivers with 30.3 dB shot noise clearance and 90.2 dB common-mode rejection ratio that downconverts the quantum optical information via homodyne detection and processes it coherently in the radio-frequency domain. With our platform, we demonstrate 32-pixel imaging of squeezed light for quantum sensing, reconfigurable free-space links for quantum communications, and proof-of-concept entanglement generation for measurement-based quantum computing. This approach offers targeted, real-time, dynamically-adjustable free-space capabilities to integrated quantum systems that can enable wireless quantum technologies.
@article{Nat2025,title={Free-space quantum information platform on a chip},month=jun,author={Gurses, Volkan and Davis, Samantha I. and Sinclair, Neil and Spiropulu, Maria and Hajimiri, Ali},year={2024},url={https://arxiv.org/abs/2406.09158},doi={10.48550/arXiv.2406.09158},dimensions={true},}
CLEO
A large-scale coherent imager with digital beamforming
Volkan Gurses, Debjit Sarkar, Aroutin Khachaturian, and 2 more authors
In Conference on Lasers and Electro-Optics (CLEO) 2024, May 2024
@article{JSTQE2022,author={Gurses, Volkan and Fatemi, Reza and Khachaturian, Aroutin and Hajimiri, Ali},journal={IEEE Journal of Selected Topics in Quantum Electronics},title={Large-scale crosstalk-corrected thermo-optic phase shifter arrays in silicon photonics},month=nov,year={2022},volume={28},number={6: High Density Integrated Multipurpose Photonic Circuits},pages={1-9},doi={10.1109/JSTQE.2022.3189965},dimensions={true},}
We present an analysis of sub-shot-noise-limited coherent receivers for detecting quantum states of light. We introduce a noise model for coherent receivers and outline a guide to coherent receiver design for silicon photonics platforms.
2021
RSI
Ultra-sensitive broadband “AWESOME” electric field receiver for nanovolt low-frequency signals
Volkan Gurses, Kevin T. Whitmore, and Morris B. Cohen
@article{RSI2021,author={Gurses, Volkan and Whitmore, Kevin T. and Cohen, Morris B.},title={{Ultra-sensitive broadband “AWESOME” electric field receiver for nanovolt low-frequency signals}},journal={Review of Scientific Instruments},month=feb,volume={92},number={2},pages={024704},year={2021},doi={10.1063/5.0031491},dimensions={true},}
2020
Broadband VLF/LF transmission from an electrically-small structure via time-varying antenna properties
Edward Slevin, Parker Singletary, Kevin Whitmore, and 5 more authors
In 2020 IEEE International Symposium on Antennas and Propagation, Jul 2020
