164 research outputs found
Oil price uncertainty as a predictor of stock market volatility
In this paper we empirically examine the impact of oil price uncertainty shocks on US stock market volatility. We define the oil price uncertainty shock as the unanticipated component of oil price fluctuations. We find that our oil price uncertainty factor is the most significant predictor of stock market volatility when compared with various observable oil price and volatility measures commonly used in the literature. Moreover, we find that oil price uncertainty is a common volatility forecasting factor of S&P500 constituents, and it outperforms lagged stock market volatility and the VIX when forecasting volatility for medium and long-term forecasting horizons. Interestingly, when forecasting the volatility of S&P500 constituents, we find that the highest predictive power of oil price uncertainty is for the stocks which belong to the financial sector. Overall, our findings show that financial stability is significantly damaged when the degree of oil price unpredictability rises, while it is relatively immune to observable fluctuations in the oil market
Deterministic protocol for mapping a qubit to coherent state superpositions in a cavity
We introduce a new gate that transfers an arbitrary state of a qubit into a
superposition of two quasi-orthogonal coherent states of a cavity mode, with
opposite phases. This qcMAP gate is based on conditional qubit and cavity
operations exploiting the energy level dispersive shifts, in the regime where
they are much stronger than the cavity and qubit linewidths. The generation of
multi-component superpositions of quasi-orthogonal coherent states, non-local
entangled states of two resonators and multi-qubit GHZ states can be
efficiently achieved by this gate
Measuring Oil Price Shocks
The role of oil price shocks in US economic activity and inflation is controversial but a key input to current economic policy. To clarify these relations, we employ a more refined measure of oil shocks based on decomposing highly accurate realized volatility estimated using intraday oil futures data. In reconciling prior results, we find that shocks driven by price increases (decreases) are associated with rising (falling) inflation while only a symmetric volatility channel affects economic activity
Hardware-efficient autonomous quantum error correction
We propose a new method to autonomously correct for errors of a logical qubit
induced by energy relaxation. This scheme encodes the logical qubit as a
multi-component superposition of coherent states in a harmonic oscillator, more
specifically a cavity mode. The sequences of encoding, decoding and correction
operations employ the non-linearity provided by a single physical qubit coupled
to the cavity. We layout in detail how to implement these operations in a
practical system. This proposal directly addresses the task of building a
hardware-efficient and technically realizable quantum memory.Comment: 12 pages,6 figure
Modelling Enclosures for Large-Scale Superconducting Quantum Circuits
Superconducting quantum circuits are typically housed in conducting
enclosures in order to control their electromagnetic environment. As devices
grow in physical size, the electromagnetic modes of the enclosure come down in
frequency and can introduce unwanted long-range cross-talk between distant
elements of the enclosed circuit. Incorporating arrays of inductive shunts such
as through-substrate vias or machined pillars can suppress these effects by
raising these mode frequencies. Here, we derive simple, accurate models for the
modes of enclosures that incorporate such inductive-shunt arrays. We use these
models to predict that cavity-mediated inter-qubit couplings and drive-line
cross-talk are exponentially suppressed with distance for arbitrarily large
quantum circuits housed in such enclosures, indicating the promise of this
approach for quantum computing. We find good agreement with a finite-element
simulation of an example device containing more than 400 qubits.Comment: 6 pages + appendix, 6 figures in main text + 4 in appendi
Single-photon Resolved Cross-Kerr Interaction for Autonomous Stabilization of Photon-number States
Quantum states can be stabilized in the presence of intrinsic and
environmental losses by either applying active feedback conditioned on an
ancillary system or through reservoir engineering. Reservoir engineering
maintains a desired quantum state through a combination of drives and designed
entropy evacuation. We propose and implement a quantum reservoir engineering
protocol that stabilizes Fock states in a microwave cavity. This protocol is
realized with a circuit quantum electrodynamics platform where a Josephson
junction provides direct, nonlinear coupling between two superconducting
waveguide cavities. The nonlinear coupling results in a single photon resolved
cross-Kerr effect between the two cavities enabling a photon number dependent
coupling to a lossy environment. The quantum state of the microwave cavity is
discussed in terms of a net polarization and is analyzed by a measurement of
its steady state Wigner function.Comment: 8 pages, 6 figure
Oil Price Uncertainty and the Macroeconomy
This paper examines the impact of oil price uncertainty shocks on economic activity. To do so, we define the uncertainty shock as the unanticipated component of oil price fluctuations. We find that this unanticipated component has a significantly negative and long-lasting impact on economic activity, with its cumulative effect on the US macroeconomy being much larger compared to that of popular uncertainty proxies such as stock market volatility and Economic Policy Uncertainty. Unlike our preferred measure of oil price uncertainty, volatility and the price spikes in oil futures prices present only a small and transitory effect on the real economy. Overall, our findings show that the US economy is significantly impaired when the degree of oil price unpredictability rises, while it is relatively immune to predictable fluctuations in the oil market
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