20 research outputs found
Quantum Information processing by NMR: Preparation of pseudopure states and implementation of unitary operations in a single-qutrit system
Theoretical Quantum Information Processing (QIP) has matured from the use of
qubits to the use of qudits (systems having states> 2). Where as most of the
experimental implementations have been performed using qubits, little
experimental work has been carried out using qudits as yet. In this paper we
demonstrate experimental realization of a qutrit system by nuclear magnetic
resonance (NMR), utilizing deuterium (spin-1) nuclei partially oriented in
liquid crystalline phase. Preparation of pseudopure states and implementation
of unitary operations are demonstrated in this single-qutrit system, using
transition selective pulses.Comment: 11 pages, 2 figure
tagE: Enabling an Embodied Agent to Understand Human Instructions
Natural language serves as the primary mode of communication when an
intelligent agent with a physical presence engages with human beings. While a
plethora of research focuses on natural language understanding (NLU),
encompassing endeavors such as sentiment analysis, intent prediction, question
answering, and summarization, the scope of NLU directed at situations
necessitating tangible actions by an embodied agent remains limited. The
inherent ambiguity and incompleteness inherent in natural language present
challenges for intelligent agents striving to decipher human intention. To
tackle this predicament head-on, we introduce a novel system known as task and
argument grounding for Embodied agents (tagE). At its core, our system employs
an inventive neural network model designed to extract a series of tasks from
complex task instructions expressed in natural language. Our proposed model
adopts an encoder-decoder framework enriched with nested decoding to
effectively extract tasks and their corresponding arguments from these
intricate instructions. These extracted tasks are then mapped (or grounded) to
the robot's established collection of skills, while the arguments find
grounding in objects present within the environment. To facilitate the training
and evaluation of our system, we have curated a dataset featuring complex
instructions. The results of our experiments underscore the prowess of our
approach, as it outperforms robust baseline models.Comment: Accepted in EMNLP Findings 202
How Gubser flow ends in a holographic conformal theory
Gubser flow is an axis-symmetric and boost-invariant evolution in a
relativistic quantum field theory, providing a model for the evolution of
matter produced in the wake of heavy-ion collisions. It is best studied by
mapping to when the field theory
has conformal symmetry. We show that at late de Sitter time, which corresponds
to large proper time and central region in , the generic
behavior for a holographic conformal field theory is given by , with , and being the energy density,
transverse and longitudinal pressures, respectively. We also establish the
general late de Sitter time expansion, which when written in a suitable basis,
systematically determines both the early proper time behavior and the behavior
at large distance from the beam axis at any fixed proper time in the Minkowski
frame. Particularly, is also generically realized
at early proper time. The late de Sitter time expansion is also consistent with
the hydrodynamic expansion at intermediate times.Comment: 10 pages, 2 figure
Certified Organization, Volume3, Special Issue 6
ABSTRACT: The paper describes the development of a low cost and simple amplifier circuit for ECG acquisition from a single lead. The acquisition circuit uses clip-type flat metal plate limb electrodes to sense the heart signals and a basic amplifier circuit is designed using JFET OP-AMP IC LF-353 with the required gain to suitably amplify the signal. The amplified data fed into a computer using USB-6009 is then denoised, processed and displayed using LabVIEW software. The developed ECG acquisition module is evaluated by visual comparison of simultaneously recorded data acquired by the module with and by the MP-150 amplifier system from BIOPAC Systems Inc. Tests have been performed in the laboratory on several volunteers in the age group of 28-60 and the results were quiet satisfactory
Experimental implementation of local adiabatic evolution algorithms by an NMR quantum information processor
Quantum adiabatic algorithm is a method of solving computational problems by
evolving the ground state of a slowly varying Hamiltonian. The technique uses
evolution of the ground state of a slowly varying Hamiltonian to reach the
required output state. In some cases, such as the adiabatic versions of
Grover's search algorithm and Deutsch-Jozsa algorithm, applying the global
adiabatic evolution yields a complexity similar to their classical algorithms.
However, using the local adiabatic evolution, the algorithms given by J. Roland
and N. J. Cerf for Grover's search [ Phys. Rev. A. {\bf 65} 042308(2002)] and
by Saurya Das, Randy Kobes and Gabor Kunstatter for the Deutsch-Jozsa algorithm
[Phys. Rev. A. {\bf 65}, 062301 (2002)], yield a complexity of order
(where N=2 and n is the number of qubits). In this paper we report
the experimental implementation of these local adiabatic evolution algorithms
on a two qubit quantum information processor, by Nuclear Magnetic Resonance.Comment: Title changed, Adiabatic Grover's search algorithm added, error
analysis modifie
Experimental implementation of quantumUlam’s problem in a nuclear magnetic resonance quantum information processor
The Ulam’s problem is a two person game in which one of the player tries to search, in minimum queries, a number thought by the other player. Classically the problem scales polynomially with the size of the number. The quantum version of the Ulam’s problem has a query complexity that is independent of the dimension of the search space.
The experimental implementation of the quantum Ulam’s problem in a Nuclear Magnetic Resonance Information Processor with 3 quantum bits is reported here
Experimental implementation of quantum Ulam's problem in a nuclear magnetic resonance quantum information processor
The Ulam's problem is a two person game in which one of the player tries to search, in minimum queries, a number thought by the other player. Classically the problem scales polynomially with the size of the number. The quantum version of the Ulam's problem has a query complexity that is independent of the dimension of the search space. The experimental implementation of the quantum Ulam's problem in a nuclear magnetic resonance information processor with 3 quantum bits is reported here
Correlation functions of the Bjorken flow in the holographic Schwinger-Keldysh approach
One of the outstanding problems in the holographic approach to many-body
physics is the computation of correlation functions of non-equilibrium states.
Here we develop the method to compute real-time correlation functions in a
holographic theory in the limit in which the state hydrodynamizes, in the
context of the Bjorken flow. Firstly, we provide a new and simple proof that
the horizon cap prescription of Crossley-Glorioso-Liu for implementing the
thermal Schwinger-Keldysh contour in the bulk is consistent with the KMS
periodicity and the ingoing boundary condition for the retarded propagator at
any arbitrary frequency and momentum. The generalization to the hydrodynamic
Bjorken flow is achieved by a Weyl rescaling in which the dual black hole's
event horizon attains a constant surface gravity and area at late time although
the directions longitudinal and transverse to the flow expands and contract
respectively. The dual state's temperature and entropy density thus become
constants (instead of undergoing perfect fluid expansion) although no
time-translation symmetry ever emerges. Undoing the Weyl rescaling, the
correlation functions can be computed systematically in a large proper time
expansion in inverse powers of the average of the two reparametrized proper
time arguments. The horizon cap has to be pinned to the non-equilibrium event
horizon so that regularity and consistency conditions are satisfied. This
mirrors causality of Schwinger-Dyson equations. In the limit of perfect fluid
expansion, the Schwinger-Keldysh correlation functions with reparametrized
spacetime arguments are simply thermal at an appropriate temperature. A
generalized bi-local thermal structure holds to all orders. We argue that the
Stokes data for the hydrodynamic correlation functions can decode the quantum
fluctuations behind the evolving event horizon, and thus the initial data.Comment: 44+13 pages; 5 figure
Experimental implementation of a three qubit quantum game with corrupt source using nuclear magnetic resonance quantum information processor
In a three player quantum 'Dilemma' game each player takes independent decisions to maximize his/her individual gain. The optimal strategy in the quantum version of this game has a higher payoff compared to its classical counterpart. However, this advantage is lost if the initial qubits provided to the players are from a noisy source. We have experimentally implemented the three player quantum version of the 'Dilemma' game as described by Johnson, [N.F. Johnson, Phys. Rev. A 63 (2001) 020302(R)] using nuclear magnetic resonance quantum information processor and have experimentally verified that the payoff of the quantum game for various levels of corruption matches the theoretical payoff