1,562 research outputs found
Producing place atmospheres digitally: Architecture, digital visualisations practices and the experience economy
Computer generated images have become the common means for architects and developers to visualise and market future urban developments. This article examines within the context of the experience economy how these digital images aim to evoke and manipulate specific place atmospheres to emphasize the experiential qualities of new buildings and urban environments. In particular, we argue that CGIs are far from âjustâ glossy representations but are a new form of visualising the urban that captures and markets particular embodied sensations. Drawing on a two year qualitative study of architectsâ practices that worked on the Msheireb project, a large scale redevelopment project in Doha (Qatar), we examine how digital visualisation technology enables the virtual engineering of sensory experiences using a wide range of graphic effects. We show how these CGIs are laboriously materialised in order to depict and present specific sensory, embodied regimes and affective experiences to appeal to clients and consumers. Such development has two key implications. Firstly, we demonstrate the importance of digital technologies in framing the âexpressive infrastructureâ (Thrift 2012) of the experience economy. Secondly, we argue that although the Msheireb CGIs open up a field of negotiation between producers and the Qatari client, and work quite hard at being culturally specific, they ultimately draw âon a Westnocentric literary and sensory paletteâ (Tolia-Kelly 2006) that highlights the continuing influence of colonial sensibilities in supposedly postcolonial urban processes.This research was funded by the ESRC (RES-062-23-0223)
Quantum sensing
"Quantum sensing" describes the use of a quantum system, quantum properties
or quantum phenomena to perform a measurement of a physical quantity.
Historical examples of quantum sensors include magnetometers based on
superconducting quantum interference devices and atomic vapors, or atomic
clocks. More recently, quantum sensing has become a distinct and rapidly
growing branch of research within the area of quantum science and technology,
with the most common platforms being spin qubits, trapped ions and flux qubits.
The field is expected to provide new opportunities - especially with regard to
high sensitivity and precision - in applied physics and other areas of science.
In this review, we provide an introduction to the basic principles, methods and
concepts of quantum sensing from the viewpoint of the interested
experimentalist.Comment: 45 pages, 13 figures. Submitted to Rev. Mod. Phy
Radio-frequency magnetometry using a single electron spin
We experimentally demonstrate a simple and robust protocol for the detection
of weak radio-frequency magnetic fields using a single electron spin in
diamond. Our method relies on spin locking, where the Rabi frequency of the
spin is adjusted to match the MHz signal frequency. In a proof-of-principle
experiment we detect a 7.5 MHz magnetic probe field of 40 nT amplitude with <10
kHz spectral resolution over a T_1-limited noise floor of 0.3 nT/rtHz.
Rotating-frame magnetometry may provide a direct and sensitive route to
high-resolution spectroscopy of nanoscale nuclear spin signals
Ultrasensitive mechanical detection of magnetic moment using a commercial disk drive write head
Sensitive detection of weak magnetic moments is an essential capability in
many areas of nanoscale science and technology, including nanomagnetism,
quantum readout of spins, and nanoscale magnetic resonance imaging. Here, we
show that the write head of a commercial hard drive may enable significant
advances in nanoscale spin detection. By approaching a sharp diamond tip to
within 5 nm from the pole and measuring the induced diamagnetic moment with a
nanomechanical force transducer, we demonstrate a spin sensitivity of 0.032
Bohr magnetons per root Hz, equivalent to 21 proton magnetic moments. The high
sensitivity is enabled in part by the pole's strong magnetic gradient of up to
28 million Tesla per meter and in part by the absence of non-contact friction
due to the extremely flat writer surface. In addition, we demonstrate
quantitative imaging of the pole field with about 10 nm spatial resolution. We
foresee diverse applications for write heads in experimental condensed matter
physics, especially in spintronics, ultrafast spin manipulation, and mesoscopic
physics.Comment: 21 pages, 6 figure
Three-dimensional nuclear spin positioning using coherent radio-frequency control
Distance measurements via the dipolar interaction are fundamental to the
application of nuclear magnetic resonance (NMR) to molecular structure
determination, but they only provide information on the absolute distance
and polar angle between spins. In this Letter, we present a protocol
to also retrieve the azimuth angle . Our method relies on measuring the
nuclear precession phase after application of a control pulse with a calibrated
external radio-frequency coil. We experimentally demonstrate three-dimensional
positioning of individual carbon-13 nuclear spins in a diamond host crystal
relative to the central electronic spin of a single nitrogen-vacancy center.
The ability to pinpoint three-dimensional nuclear locations is central for
realizing a nanoscale NMR technique that can image the structure of single
molecules with atomic resolution.Comment: 5 pages, 4 figure
High-bandwidth microcoil for fast nuclear spin control
The active manipulation of nuclear spins with radio-frequency (RF) coils is
at the heart of nuclear magnetic resonance (NMR) spectroscopy and spin-based
quantum devices. Here, we present a microcoil transmitter system designed to
generate strong RF pulses over a broad bandwidth, allowing for fast spin
rotations on arbitrary nuclear species. Our design incorporates: (i) a planar
multilayer geometry that generates a large field of 4.35 mT per unit current,
(ii) a 50 Ohm transmission circuit with a broad excitation bandwidth of
approximately 20 MHz, and (iii) an optimized thermal management for removal of
Joule heating. Using individual 13C nuclear spins in the vicinity of a diamond
nitrogen-vacancy (NV) center as a test system, we demonstrate Rabi frequencies
exceeding 70 kHz and nuclear pi/2 rotations within 3.4 us. The extrapolated
values for 1H spins are about 240 kHz and 1 us, respectively. Beyond enabling
fast nuclear spin manipulations, our microcoil system is ideally suited for the
incorporation of advanced pulse sequences into micro- and nanoscale NMR
detectors operating at low (<1 T) magnetic field.Comment: 8 pages, 5 figures. Submitted to Rev. Sci. Inst
Quantum sensing with arbitrary frequency resolution
Quantum sensing takes advantage of well controlled quantum systems for
performing measurements with high sensitivity and precision. We have
implemented a concept for quantum sensing with arbitrary frequency resolution,
independent of the qubit probe and limited only by the stability of an external
synchronization clock. Our concept makes use of quantum lock-in detection to
continuously probe a signal of interest. Using the electronic spin of a single
nitrogen vacancy center in diamond, we demonstrate detection of oscillating
magnetic fields with a frequency resolution of 70 uHz over a MHz bandwidth. The
continuous sampling further guarantees an excellent sensitivity, reaching a
signal-to-noise ratio in excess of 10,000:1 for a 170 nT test signal measured
during a one-hour interval. Our technique has applications in magnetic
resonance spectroscopy, quantum simulation, and sensitive signal detection.Comment: Manuscript resubmitted to Science. Includes Supplementary Material
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