49 citations · 213 across the 10 of their papers we have counts for
10 papers
Characterizing gate operations near the sweet spot of an exchange-only qubit
Jianjia Fei, Jo-Tzu Hung, Teck Seng Koh +4
Optimal working points or "sweet spots" have arisen as an important tool for mitigating charge noise in quantum dot logical spin qubits. The exchange-only qubit provides an ideal s…
Numerical Computations of Separability Probabilities
Jianjia Fei, Robert Joynt
We compute the probability that a bipartite quantum state is separable by Monte Carlo sampling. This is carried out for rebits, qubits and quaterbits. We sampled …
Decoherence of an exchange qubit by hyperfine interaction
Jo-Tzu Hung, Jianjia Fei, Mark Friesen +1
We study three-electron-spin decoherence in a semiconductor triple quantum dot with a linear geometry. The three electron spins are coupled by exchange interactions J_{12} and J_{2…
Single-qubit gates in two steps with rotation axes in a single plane
Yun-Pil Shim, Jianjia Fei, Sangchul Oh +2
Any single-qubit unitary operation or quantum gate can be considered a rotation. Typical experimental implementations of single-qubit gates involve two or three fixed rotation axes…
Probing Quantum Phase Transitions on a Spin Chain with a Double Quantum Dot
Yun-Pil Shim, Sangchul Oh, Jianjia Fei +2
Quantum phase transitions (QPTs) in qubit systems are known to produce singularities in the entanglement, which could in turn be used to probe the QPT. Current proposals to measure…
Mediated gates between spin qubits
Jianjia Fei, Dong Zhou, Yun-Pil Shim +3
In a typical quantum circuit, nonlocal quantum gates are applied to nonproximal qubits. If the underlying physical interactions are short-range (e.g., exchange interactions between…
Resonant Adiabatic Passage with Three Qubits
Sangchul Oh, Yun-Pil Shim, Jianjia Fei +2
We investigate the non-adiabatic implementation of an adiabatic quantum teleportation protocol, finding that perfect fidelity can be achieved through resonance. We clarify the phys…
Heisenberg Spin Bus as a Robust Transmission Line for Perfect State Transfer
Sangchul Oh, Lian-Ao Wu, Yun-Pil Shim +2
We study the protocol known as quantum state transfer for a strongly coupled antiferromagnetic spin chain or ring (acting as a spin bus), with weakly coupled external qubits. By tr…
Effect of Randomness on Quantum Data Buses of Heisenberg Spin Chains
Sangchul Oh, Yun-Pil Shim, Jianjia Fei +2
A strongly coupled spin chain can mediate long-distance effective couplings or entanglement between remote qubits, and can be used as a quantum data bus. We study how the fidelity…
Topology of Entanglement Evolution of Two Qubits
Dong Zhou, Gia-Wei Chern, Jianjia Fei +1
The dynamics of a two-qubit system is considered with the aim of a general categorization of the different ways in which entanglement can disappear in the course of the evolution,…