Bose Einstein Condensate As New Form of Matter

Bose Einstein Condensate as New Form of Matter

Vinit Kumar Lohan

Assistant Professor, Vaish College of Engineering, Rohtak, Haryana (India)

Abstract of a Bose gas, governed by Bose–Einstein statistics, This paper explains the main idea of Bose Einstein which describes the statistical distribution of identical condensate. Here is explained about the current and particles with integer spin, now called bosons. historical perspective of this form of matter. It is also Bosons, which include the photon as well as atoms explained how this concept of BE Condensate came in such as helium-4 (4He), are allowed to share a existence and how the two big names SN Bose and Einstein quantum state. Einstein proposed that cooling work on this concept. The change in different phases with temperature is explained pictorially in this article. bosonic atoms to a very low temperature would cause Keywords: Bose Einstein Condensate, Phase them to fall (or "condense") into the lowest accessible Transition, Quantum Statistics. quantum state, resulting in a new form of matter. In 1938 Fritz London proposed BEC as a mechanism 1. Introduction for superfluidity in 4He and superconductivity.

A Bose–Einstein condensate (BEC) is a state of On June 5, 1995 the first gaseous condensate was matter of a dilute gas of bosons cooled to produced by Eric Cornell and Carl Wieman at the temperatures very close to absolute zero (that is, very University of Colorado at Boulder NIST–JILA lab, in near 0 K or −273.16 °C). Under such conditions, a a gas of rubidium atoms cooled to 170 nanokelvin large fraction of bosons occupy the lowest quantum (nK). Shortly thereafter, Wolfgang Ketterle at MIT state, at which point macroscopic quantum demonstrated important BEC properties. For their phenomena become apparent. This state was first achievements Cornell, Wieman, and Ketterle predicted, generally, in 1924–25 by Satyendra Nath received the 2001 Nobel Prize in Physics. Bose and Albert Einstein. This transition to BEC Many isotopes were soon condensed, then molecules, occurs below a critical temperature, which for a quasi-particles, and photons in 2010. uniform three-dimensional gas consisting of non- interacting particles with no apparent internal degrees of freedom. 3. Current Work Perspective

Compared to more commonly encountered states of 2. Historical Perspective matter, Bose–Einstein condensates are extremely fragile. The slightest interaction with the external Satyendra Nath Bose first sent a paper to Einstein on environment can be enough to warm them past the the quantum statistics of light quanta (now called condensation threshold, eliminating their interesting photons), deriving Planck's quantum radiation law properties and forming a normal gas. without any reference to classical physics, and Einstein was impressed, translated the paper himself Nevertheless, they have proven useful in exploring a from English to German and submitted it for Bose to wide range of questions in fundamental physics, and the Zeitschrift für Physik, which published it. (The the years since the initial discoveries by the JILA and Einstein manuscript, once believed to be lost, was MIT groups have seen an increase in experimental found in a library at Leiden University in 2005.). and theoretical activity. Examples include Einstein then extended Bose's ideas to matter in two experiments that have demonstrated interference other papers. The result of their efforts is the concept between condensates due to wave–particle duality, IJPCMF www.ijpcmf.com 5

IJPCMF International Journal of Physics, Chemistry and Mathematical Fundamentals, Vol. 15, Issue 01 Publishing Month: March 2016 An Indexed and Referred Journal with Impact Factor: 2.12 ISSN: 2278-1846 www.ijpcmf.com the study of superfluidity and quantized vortices, the condensation, the fermions must "pair up" to form creation of bright matter wave solitons from Bose bosonic compound particles (e.g. molecules or condensates confined to one dimension, and the Cooper pairs). The first molecular condensates were slowing of light pulses to very low speeds using created in November 2003 by the groups of Rudolf electromagnetically induced transparency. Vortices in Grimm at the University of Innsbruck, Deborah S. Jin Bose–Einstein condensates are also currently the at the University of Colorado at Boulder and subject of analogue gravity research, studying the Wolfgang Ketterle at MIT. Jin quickly went on to possibility of modeling black holes and their related create the first fermionic condensate composed of phenomena in such environments in the laboratory. Cooper pairs. Experimenters have also realized "optical lattices", where the interference pattern from overlapping In 1999, Danish physicist Lene Hau led a team from lasers provides a periodic potential. These have been Harvard University which slowed a beam of light to used to explore the transition between a superfluid about 17 meters per second.[clarification needed], and a Mott insulator, and may be useful in studying using a superfluid. Hau and her associates have since Bose–Einstein condensation in fewer than three made a group of condensate atoms recoil from a light dimensions, for example the Tonks–Girardeau gas. pulse such that they recorded the light's phase and amplitude, recovered by a second nearby condensate, Bose–Einstein condensates composed of a wide in what they term "slow-light-mediated atomic range of isotopes have been produced. matter-wave amplification" using Bose–Einstein condensates: details are discussed in Nature. Cooling fermions to extremely low temperatures has created degenerate gases, subject to the Pauli The graph showing how different phases changes exclusion principle. To exhibit Bose–Einstein with temperature are changing shown below:

Figure 1: Phase Change with Temperature

IJPCMF www.ijpcmf.com 6

Researchers in the new field of atomtronics use the properties of Bose–Einstein condensates when manipulating groups of identical cold atoms using lasers. Further, BECs have been proposed by Emmanuel David Tannenbaum for anti-stealth technology.

4. Conclusion and Future Perspectives

There are many forms of matter solid, liquid, gas and plasma. But Bose Einstein Condensate can be studied as a separate form of matter. A lot of work is done on this condensate still this form of matter is as a topic of interest for researchers. Many applications of this form can be studied in future. This concept can be used as a quantum simulator in which quantum mass acquisition of particles can be observed.

References

[1] Clark, Ronald W (1971) Einstein: The Life and Times. Avon Books. pp. 408–409 ISBN 0-380- 01159-X. [2] London, F. (1938) "The λ-Phenomenon of Liquid Helium and the Bose–Einstein Degeneracy" Nature 141 (3571): 643–644 Bibcode: 1938 Nature doi: 10.1038/141643a0. [3] London, F. Superfluids Vol. I and II, (reprinted New York: Dover 1964) [4] http://www.nist.gov/public_affairs/releases/bec_ background.cfm [5] Levi, Barbara Goss "Cornell, Ketterle, and Wieman Share Nobel Prize for Bose–Einstein Condensates" Search & Discovery, Physics Today online Archived from the original on 24 October 2007.

IJPCMF www.ijpcmf.com 7