Liang Jiang

Routing entanglement in the quantum internet

2019 · npj Quantum Information

Abstract Remote quantum entanglement can enable numerous applications including distributed quantum computation, secure communication, and precision sensing. We consider how a quantum network—nodes equipped with limited quantum processing capabilities connected via lossy optical links—can distribute …

Robust readout of bosonic qubits in the dispersive coupling regime

2018 · Physical Review A

High-fidelity qubit measurements play a crucial role in quantum computation, communication, and metrology. In recent experiments, it has been shown that readout fidelity can be improved by performing repeated quantum nondemolition (QND) readouts of a …

Hardware-Efficient Quantum Random Access Memory with Hybrid Quantum Acoustic Systems

2019 · Physical Review Letters

Hybrid quantum systems in which acoustic resonators couple to superconducting qubits are promising quantum information platforms. High quality factors and small mode volumes make acoustic modes ideal quantum memories, while the qubit-phonon coupling enables the …

Universal Control of an Oscillator with Dispersive Coupling to a Qubit

2015 · arXiv (Cornell University)

We investigate quantum control of an oscillator mode off-resonantly coupled to an ancillary qubit. In the strong dispersive regime, we may drive the qubit conditioned on number states of the oscillator, which together with displacement …

Interference-based universal decoupling and swapping for multimode bosonic systems

2020 · arXiv (Cornell University)

Beam-splitter operations are widely used to process information encoded in bosonic modes. In hybrid quantum systems, however, it might be challenging to implement a reliable beam-splitter operation between two distinct bosonic modes. Without beam-splitters, some …

Quantum capacity and codes for the bosonic loss-dephasing channel

2022 · arXiv (Cornell University)

Bosonic qubits encoded in continuous-variable systems provide a promising alternative to two-level qubits for quantum computation and communication. So far, photon loss has been the dominant source of errors in bosonic qubits, but the significant …

Construction of Bias-preserving Operations for Pair-cat Code

2022 · arXiv (Cornell University)

Fault-tolerant quantum computation with depolarization error often requires demanding error threshold and resource overhead. If the operations can maintain high noise bias -- dominated by dephasing error with small bit-flip error -- we can achieve …

Towards provably efficient quantum algorithms for large-scale machine-learning models

2023 · arXiv (Cornell University)

Large machine learning models are revolutionary technologies of artificial intelligence whose bottlenecks include huge computational expenses, power, and time used both in the pre-training and fine-tuning process. In this work, we show that fault-tolerant quantum …

Improve Interpretability of Neural Networks via Sparse Contrastive Coding

2022

Although explainable artificial intelligence (XAI) has achieved remarkable developments in recent years, there are few efforts have been devoted to the following problems, namely, i) how to develop an explainable method that could explain the …

Universal Spreading of Conditional Mutual Information in Noisy Random Circuits

2024 · arXiv (Cornell University)

We study the evolution of conditional mutual information in generic open quantum systems, focusing on one-dimensional random circuits with interspersed local noise. Unlike in noiseless circuits, where conditional mutual information spreads linearly while being bounded …

Dark Spin-Cat States as Biased Qubits

2025 · Physical Review Letters

We present a biased atomic qubit, universally implementable across all atomic platforms, encoded as a "spin cat" within ground state Zeeman levels. The key characteristic of our configuration is the coupling of the ground state …

Stochastic noise can be helpful for variational quantum algorithms

2025 · Physical Review A

Saddle points constitute a crucial challenge for first-order gradient descent algorithms. In notions of classical machine learning, they are avoided, for example, by means of stochastic gradient descent methods. In this work, we provide evidence …

Implementation of a Quantum Addressable Router Using Superconducting Qubits

2025 · arXiv (Cornell University)

The implementation of a quantum router capable of performing both quantum signal routing and quantum addressing (a Q2-router) represents a key step toward building quantum networks and quantum random access memories. We realize a Q2-router …