Stefan Krastanov
Yale University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Stefan Krastanov.
Physical Review Letters | 2015
Reinier Heeres; Brian Vlastakis; Eric Holland; Stefan Krastanov; Victor V. Albert; Luigi Frunzio; Liang Jiang; R. J. Schoelkopf
The large available Hilbert space and high coherence of cavity resonators make these systems an interesting resource for storing encoded quantum bits. To perform a quantum gate on this encoded information, however, complex nonlinear operations must be applied to the many levels of the oscillator simultaneously. In this work, we introduce the selective number-dependent arbitrary phase (snap) gate, which imparts a different phase to each Fock-state component using an off-resonantly coupled qubit. We show that the snap gate allows control over the quantum phases by correcting the unwanted phase evolution due to the Kerr effect. Furthermore, by combining the snap gate with oscillator displacements, we create a one-photon Fock state with high fidelity. Using just these two controls, one can construct arbitrary unitary operations, offering a scalable route to performing logical manipulations on oscillator-encoded qubits.
Bulletin of the American Physical Society | 2015
Stefan Krastanov; Victor V. Albert; Chao Shen; Chang-Ling Zou; Reinier Heeres; Brian Vlastakis; R. J. Schoelkopf; Liang Jiang
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 the number states of the oscillator, which, together with displacement operations, can achieve universal control of the oscillator. Based on our proof of universal control, we provide a straightforward recipe to perform arbitrary unitary operations on the oscillator. With the capability of universal control, we can significantly reduce the number of operations to prepare the number state
Scientific Reports | 2017
Stefan Krastanov; Liang Jiang
\left|n\right\ensuremath{\rangle}
Physical Review B | 2017
Chao Shen; Kyungjoo Noh; Victor V. Albert; Stefan Krastanov; Michel H. Devoret; R. J. Schoelkopf; S. M. Girvin; Liang Jiang
from
Physical Review Letters | 2016
Victor V. Albert; Chi Shu; Stefan Krastanov; Chao Shen; Ren-Bao Liu; Zhen-Biao Yang; R. J. Schoelkopf; Mazyar Mirrahimi; Michel H. Devoret; Liang Jiang
O\left(n\right)
arXiv: Quantum Physics | 2015
Victor V. Albert; Stefan Krastanov; Chao Shen; Ren-Bao Liu; R. J. Schoelkopf; Mazyar Mirrahimi; Michel H. Devoret; Liang Jiang
to
Archive | 2016
Reinier Heeres; Brian Vlastakis; Victor V. Albert; Stefan Krastanov; Liang Jiang; Iii Robert J. Schoelkopf
O\left(\sqrt{n}\right)
Bulletin of the American Physical Society | 2018
Stefan Krastanov; Liang Jiang
. This universal control scheme of the oscillator enables us to efficiently manipulate the quantum information stored in the oscillator, which can be implemented using superconducting circuits.
arXiv: Quantum Physics | 2017
Stefan Krastanov; Victor V. Albert; Liang Jiang
Neural networks can efficiently encode the probability distribution of errors in an error correcting code. Moreover, these distributions can be conditioned on the syndromes of the corresponding errors. This paves a path forward for a decoder that employs a neural network to calculate the conditional distribution, then sample from the distribution - the sample will be the predicted error for the given syndrome. We present an implementation of such an algorithm that can be applied to any stabilizer code. Testing it on the toric code, it has higher threshold than a number of known decoders thanks to naturally finding the most probable error and accounting for correlations between errors.
Bulletin of the American Physical Society | 2017
Chao Shen; Kyungjoo Noh; Victor V. Albert; Stefan Krastanov; Michel H. Devoret; R. J. Schoelkopf; S. M. Girvin; Liang Jiang
Quantum channels can describe all transformations allowed by quantum mechanics. We provide an explicit universal protocol to construct all possible quantum channels, using a single qubit ancilla with quantum non-demolition readout and adaptive control. Our construction is efficient in both physical resources and circuit depth, and can be demonstrated using superconducting circuits and various other physical platforms. There are many applications of quantum channel construction, including system stabilization and quantum error correction, Markovian and exotic channel simulation, implementation of generalized quantum measurements and more general quantum instruments. Efficient construction of arbitrary quantum channels opens up exciting new possibilities for quantum control, quantum sensing and information processing tasks.