Stanford physicists make new form of matter

The laser-cooled quantum gas opens exciting new

realms of unconventional superconductivity.

By Max McClure
Stanford University News

Within the exotic world of macroscopic quantum

effects, where fluids flow uphill, wires conduct without

electrical resistance and magnets levitate, there is an

even stranger family of “unconventional” phenomena:

strongly interacting fermions, a class of particles that

are often very difficult to understand on the quantum

level. These materials often defy explanation by

current theoretical physics, but hold enormous

promise for the development of futuristic technologies

as room-temperature superconductors, ultrasensitive

microscopes and quantum computation.

Last week the scientific world was appalled when

a Stanford team made the announcement in Physical

Review Letters that they had created the world’s first

dipolar quantum fermionic gas– “an entirely new

form of quantum matter,” as Stanford applied physics

Professor and lead author Benjamin Lev puts it. Lev

affirmed that this development represents a major

step toward understanding the behavior of these

systems of particles. Until now, research efforts had

focused on cooling bosons – fundamentally different

from fermions, and much easier to work with. But

now the Stanford team extended these techniques to

gases made of the most magnetic atom: a fermionic

isotope of dysprosium with magnetic energies 4

times larger than previously cooled gases.

He explained that when the thermal energy of

some substances drops below a certain critical point,

it used to be impossible to consider its component

particles separately since the material becomes

strongly correlated and its quantum effects become

difficult to understand and study. Nevertheless,

making the material out of a gas of atoms allows it

to become visible. These quantum gases, the coldest

objects known to man, are where researchers can

observe zero-viscosity fluids – superfluids – that are

mathematical cousins of superconductors.

Thus far, the result of the Lev lab’s high-tech efforts

is a tiny ball of ultracold quantum dipolar fluid. But the

researchers have reason to believe that the humble

substance will exhibit the seemingly contradictory

characteristics of both crystals and superfluids. This

combination could lead to quantum liquid crystals.

Or it could yield a supersolid – a hypothetical state

of matter that would, in theory at least, be a solid with

superfluid characteristics.

The researchers have already begun developing a

microscope to make use of the dipolar quantum fluid’s

unique characteristics. It is the “cryogenic atom chip

microscope”, a magnetic probe that should measure

magnetic fields with unprecedented sensitivity and

resolution. “This kind of probe may even allow for a

more stable form of quantum computation that uses

exotic quantum matter to process information, known

as a topologically protected quantum computer”,

said Lev. “So this new approach is really incredibly

exciting.”

Available at: http://news.stanford.edu/news/2012/june/lev-new--matter-060512.html. Retrieved on: 5 June 2012. Adapted.

Stanford physicists make new form of matter

The laser-cooled quantum gas opens exciting new

realms of unconventional superconductivity.

By Max McClure
Stanford University News

Within the exotic world of macroscopic quantum

effects, where fluids flow uphill, wires conduct without

electrical resistance and magnets levitate, there is an

even stranger family of “unconventional” phenomena:

strongly interacting fermions, a class of particles that

are often very difficult to understand on the quantum

level. These materials often defy explanation by

current theoretical physics, but hold enormous

promise for the development of futuristic technologies

as room-temperature superconductors, ultrasensitive

microscopes and quantum computation.

Last week the scientific world was appalled when

a Stanford team made the announcement in Physical

Review Letters that they had created the world’s first

dipolar quantum fermionic gas– “an entirely new

form of quantum matter,” as Stanford applied physics

Professor and lead author Benjamin Lev puts it. Lev

affirmed that this development represents a major

step toward understanding the behavior of these

systems of particles. Until now, research efforts had

focused on cooling bosons – fundamentally different

from fermions, and much easier to work with. But

now the Stanford team extended these techniques to

gases made of the most magnetic atom: a fermionic

isotope of dysprosium with magnetic energies 4

times larger than previously cooled gases.

He explained that when the thermal energy of

some substances drops below a certain critical point,

it used to be impossible to consider its component

particles separately since the material becomes

strongly correlated and its quantum effects become

difficult to understand and study. Nevertheless,

making the material out of a gas of atoms allows it

to become visible. These quantum gases, the coldest

objects known to man, are where researchers can

observe zero-viscosity fluids – superfluids – that are

mathematical cousins of superconductors.

Thus far, the result of the Lev lab’s high-tech efforts

is a tiny ball of ultracold quantum dipolar fluid. But the

researchers have reason to believe that the humble

substance will exhibit the seemingly contradictory

characteristics of both crystals and superfluids. This

combination could lead to quantum liquid crystals.

Or it could yield a supersolid – a hypothetical state

of matter that would, in theory at least, be a solid with

superfluid characteristics.

The researchers have already begun developing a

microscope to make use of the dipolar quantum fluid’s

unique characteristics. It is the “cryogenic atom chip

microscope”, a magnetic probe that should measure

magnetic fields with unprecedented sensitivity and

resolution. “This kind of probe may even allow for a

more stable form of quantum computation that uses

exotic quantum matter to process information, known

as a topologically protected quantum computer”,

said Lev. “So this new approach is really incredibly

exciting.”

Available at: http://news.stanford.edu/news/2012/june/lev-new--matter-060512.html. Retrieved on: 5 June 2012. Adapted.

Stanford physicists make new form of matter

The laser-cooled quantum gas opens exciting new

realms of unconventional superconductivity.

By Max McClure
Stanford University News

Within the exotic world of macroscopic quantum

effects, where fluids flow uphill, wires conduct without

electrical resistance and magnets levitate, there is an

even stranger family of “unconventional” phenomena:

strongly interacting fermions, a class of particles that

are often very difficult to understand on the quantum

level. These materials often defy explanation by

current theoretical physics, but hold enormous

promise for the development of futuristic technologies

as room-temperature superconductors, ultrasensitive

microscopes and quantum computation.

Last week the scientific world was appalled when

a Stanford team made the announcement in Physical

Review Letters that they had created the world’s first

dipolar quantum fermionic gas– “an entirely new

form of quantum matter,” as Stanford applied physics

Professor and lead author Benjamin Lev puts it. Lev

affirmed that this development represents a major

step toward understanding the behavior of these

systems of particles. Until now, research efforts had

focused on cooling bosons – fundamentally different

from fermions, and much easier to work with. But

now the Stanford team extended these techniques to

gases made of the most magnetic atom: a fermionic

isotope of dysprosium with magnetic energies 4

times larger than previously cooled gases.

He explained that when the thermal energy of

some substances drops below a certain critical point,

it used to be impossible to consider its component

particles separately since the material becomes

strongly correlated and its quantum effects become

difficult to understand and study. Nevertheless,

making the material out of a gas of atoms allows it

to become visible. These quantum gases, the coldest

objects known to man, are where researchers can

observe zero-viscosity fluids – superfluids – that are

mathematical cousins of superconductors.

Thus far, the result of the Lev lab’s high-tech efforts

is a tiny ball of ultracold quantum dipolar fluid. But the

researchers have reason to believe that the humble

substance will exhibit the seemingly contradictory

characteristics of both crystals and superfluids. This

combination could lead to quantum liquid crystals.

Or it could yield a supersolid – a hypothetical state

of matter that would, in theory at least, be a solid with

superfluid characteristics.

The researchers have already begun developing a

microscope to make use of the dipolar quantum fluid’s

unique characteristics. It is the “cryogenic atom chip

microscope”, a magnetic probe that should measure

magnetic fields with unprecedented sensitivity and

resolution. “This kind of probe may even allow for a

more stable form of quantum computation that uses

exotic quantum matter to process information, known

as a topologically protected quantum computer”,

said Lev. “So this new approach is really incredibly

exciting.”

Available at: http://news.stanford.edu/news/2012/june/lev-new--matter-060512.html. Retrieved on: 5 June 2012. Adapted.

Stanford physicists make new form of matter

The laser-cooled quantum gas opens exciting new

realms of unconventional superconductivity.

By Max McClure
Stanford University News

Within the exotic world of macroscopic quantum

effects, where fluids flow uphill, wires conduct without

electrical resistance and magnets levitate, there is an

even stranger family of “unconventional” phenomena:

strongly interacting fermions, a class of particles that

are often very difficult to understand on the quantum

level. These materials often defy explanation by

current theoretical physics, but hold enormous

promise for the development of futuristic technologies

as room-temperature superconductors, ultrasensitive

microscopes and quantum computation.

Last week the scientific world was appalled when

a Stanford team made the announcement in Physical

Review Letters that they had created the world’s first

dipolar quantum fermionic gas– “an entirely new

form of quantum matter,” as Stanford applied physics

Professor and lead author Benjamin Lev puts it. Lev

affirmed that this development represents a major

step toward understanding the behavior of these

systems of particles. Until now, research efforts had

focused on cooling bosons – fundamentally different

from fermions, and much easier to work with. But

now the Stanford team extended these techniques to

gases made of the most magnetic atom: a fermionic

isotope of dysprosium with magnetic energies 4

times larger than previously cooled gases.

He explained that when the thermal energy of

some substances drops below a certain critical point,

it used to be impossible to consider its component

particles separately since the material becomes

strongly correlated and its quantum effects become

difficult to understand and study. Nevertheless,

making the material out of a gas of atoms allows it

to become visible. These quantum gases, the coldest

objects known to man, are where researchers can

observe zero-viscosity fluids – superfluids – that are

mathematical cousins of superconductors.

Thus far, the result of the Lev lab’s high-tech efforts

is a tiny ball of ultracold quantum dipolar fluid. But the

researchers have reason to believe that the humble

substance will exhibit the seemingly contradictory

characteristics of both crystals and superfluids. This

combination could lead to quantum liquid crystals.

Or it could yield a supersolid – a hypothetical state

of matter that would, in theory at least, be a solid with

superfluid characteristics.

The researchers have already begun developing a

microscope to make use of the dipolar quantum fluid’s

unique characteristics. It is the “cryogenic atom chip

microscope”, a magnetic probe that should measure

magnetic fields with unprecedented sensitivity and

resolution. “This kind of probe may even allow for a

more stable form of quantum computation that uses

exotic quantum matter to process information, known

as a topologically protected quantum computer”,

said Lev. “So this new approach is really incredibly

exciting.”

Available at: http://news.stanford.edu/news/2012/june/lev-new--matter-060512.html. Retrieved on: 5 June 2012. Adapted.

Stanford physicists make new form of matter

The laser-cooled quantum gas opens exciting new

realms of unconventional superconductivity.

By Max McClure
Stanford University News

Within the exotic world of macroscopic quantum

effects, where fluids flow uphill, wires conduct without

electrical resistance and magnets levitate, there is an

even stranger family of “unconventional” phenomena:

strongly interacting fermions, a class of particles that

are often very difficult to understand on the quantum

level. These materials often defy explanation by

current theoretical physics, but hold enormous

promise for the development of futuristic technologies

as room-temperature superconductors, ultrasensitive

microscopes and quantum computation.

Last week the scientific world was appalled when

a Stanford team made the announcement in Physical

Review Letters that they had created the world’s first

dipolar quantum fermionic gas– “an entirely new

form of quantum matter,” as Stanford applied physics

Professor and lead author Benjamin Lev puts it. Lev

affirmed that this development represents a major

step toward understanding the behavior of these

systems of particles. Until now, research efforts had

focused on cooling bosons – fundamentally different

from fermions, and much easier to work with. But

now the Stanford team extended these techniques to

gases made of the most magnetic atom: a fermionic

isotope of dysprosium with magnetic energies 4

times larger than previously cooled gases.

He explained that when the thermal energy of

some substances drops below a certain critical point,

it used to be impossible to consider its component

particles separately since the material becomes

strongly correlated and its quantum effects become

difficult to understand and study. Nevertheless,

making the material out of a gas of atoms allows it

to become visible. These quantum gases, the coldest

objects known to man, are where researchers can

observe zero-viscosity fluids – superfluids – that are

mathematical cousins of superconductors.

Thus far, the result of the Lev lab’s high-tech efforts

is a tiny ball of ultracold quantum dipolar fluid. But the

researchers have reason to believe that the humble

substance will exhibit the seemingly contradictory

characteristics of both crystals and superfluids. This

combination could lead to quantum liquid crystals.

Or it could yield a supersolid – a hypothetical state

of matter that would, in theory at least, be a solid with

superfluid characteristics.

The researchers have already begun developing a

microscope to make use of the dipolar quantum fluid’s

unique characteristics. It is the “cryogenic atom chip

microscope”, a magnetic probe that should measure

magnetic fields with unprecedented sensitivity and

resolution. “This kind of probe may even allow for a

more stable form of quantum computation that uses

exotic quantum matter to process information, known

as a topologically protected quantum computer”,

said Lev. “So this new approach is really incredibly

exciting.”

Available at: http://news.stanford.edu/news/2012/june/lev-new--matter-060512.html. Retrieved on: 5 June 2012. Adapted.

bilhões: expresso Terra lotado

Um menino pobre nascido em outubro de 2011,

na Índia, pode imprimir um novo marco na história,

por ser o sétimo bilionésimo habitante do planeta.

Todas as estatísticas convergem: o país tem o maior

número de nascimentos no mundo – 27 milhões por

ano – e a incidência natural de nascimentos por sexo,

na região, favorece os meninos. Em 2018, a Índia de-

terá o “inacreditável” título de país mais populoso do

mundo, à frente da China.

O expresso Terra está lotado, mas é preciso dar

“mais um passinho à frente” para acomodar 9 bilhões

em 2030. Como vamos fazer isso?

Todas as gerações tiveram o seu “profeta do apo-

calipse” demográfico. Porém a grande crise não che-

ga, e a contagem aumenta, ano após ano, atualizan-

do a pergunta recorrente: até quando? Não há limite?

Quanta gente cabe no mundo? Afinal, há apenas

anos o planeta possuía 6 bilhões de habitantes. Há

100, em 1911, éramos somente 1,6 bilhão.

Uma resposta à ansiedade pode ser “9 bilhões”.

Segundo a ONU, a população mundial deverá estabi-

lizar-se em torno de 2050, atingindo o equilíbrio entre

nascimentos e mortes, com uma população entre

bilhões e 10,5 bilhões de habitantes - se não houver

imprevistos. A melhor aposta é 9 bilhões, em 2045.

Depois desse patamar, os números deverão começar

a diminuir, uma vez que o crescimento já estagnou na

maioria dos países em desenvolvimento.

O problema será organizar 9 bilhões. Sete bi-

lhões já dão trabalho. “É óbvio que, quanto mais

gente existir, maiores serão os impactos ambientais

e sociais”, diz o biólogo Paul Ehrlich, da Universidade

Stanford, nos Estados Unidos. “Os 2 bilhões a mais

até 2050 gerarão muito mais dano ambiental do que

os últimos 2 bilhões agregados, porque os padrões

de consumo são mais intensivos”, ressalta.

Mas o olhar pessimista também pode ser inver-

tido, e o crescimento demográfico ser visto como

sinal de prosperidade. A mortalidade infantil declina

e a expectativa de vida aumenta na maior parte dos

países. O esgoto, o saneamento e o tratamento da

água corrigiram a incubação de pestes e doenças

nas cidades, como tifo e cólera. A higiene e os anti-

bióticos elevaram a expectativa de vida europeia de

anos, em 1800, para 77 anos, em 2010. Apesar

da desigualdade do desenvolvimento tecnológico,

depois da Segunda Guerra Mundial os antibióticos e

a Revolução Verde ampliaram enormemente os po-

deres da medicina e da agricultura. A biotecnologia e

os alimentos processados industrialmente tornaram

os surtos de fome “nacionais” mais raros, mesmo am-

pliando o risco de epidemias, como a da vaca louca,

em 1992. Além disso, o crescimento econômico vem

aumentando a prosperidade dos países.

Com tanto crescimento, a espaçonave Terra

está cada vez mais pesada. Os cálculos indicam que

o consumo global ultrapassou a capacidade de rege-

neração do planeta em 1987 e, se continuarmos no

ritmo atual, a humanidade precisará de dois planetas.

Para os ambientalistas, a demanda econômica está

erodindo o solo, esgotando a água, poluindo a atmos-

fera e gerando montanhas de lixo cada vez maiores.

A espécie humana talvez seja uma “praga” sobre a

Terra.

ARNT, Ricardo. 7 bilhões: expresso Terra lotado Revista Planeta. São Paulo: Editora Três. jun. 2011, ano 39, n. 465. p. 22-28. Adaptado